The last Arc feels extremely rushed. There was so much left to expand on and I think he just couldn't because the arc would be drawn out way to long probably.
The Royal guard. It was said that the royal guard was stronger than the entire Gotei 13. Meanwhile the entire guard get taken out to the Sternritter. It wouldn't be so bad if not for two things. First, they get taken out without really even putting up a fight, the fight was so bad that they weren't even given any show time when they got taken out, it was all done off scene, when Yhwach fight's Ichibe another fight that didn't last long and that with Ichibe being one of the great 5 war powers(Ichigo, Ichibe, Zaraki, Urihara, Aizen).
The second is that the Sternritter weren't even in their ultimate form when they defeated the Royal Guard. Meanwhile the Gotei 13 push the Sternritter to their final forms and defeat them. The only arguements that could be made is that Urihara isn't considered the Gotei 13 anymore and that him and Kenpachi are considered one of the 5 war powers and explains why they won or did so well against them. That being said, the Gotei 13 did leagues better than the Royal Guard did. Another example of power level balance/information lacking from Tite Kubo.
Bazz-B and Hashwalth story is a little inconsistent. First they train hard so that they can join Yhwach to kill him. Yet when they are going to join, they are emotions of betrayal when Haschwalth gets picked and not Bazz-b. Like who cares, you guys are going to kill Yhwach why does it matter who he picks. Bazz loses sight of this and joins just to defeat Haschwalth. Then when Yhwach takes his power and tries to kill him, he goes full "I'm going to kill Yhwach" ..............huh?! Did you forget this was the whole POINT of joining his forces? Now you remember you have to kill him?? what... Lets not forget Haschwalth also forgets he was going to try to kill him too. All of a sudden Yhwach is someone Haschwalth has to survive no matter what.
Aizen is hyped up like as if he's actually going to do something. Lets be honest if you are an Aizen fan, you really wanted to see this, you wanted to see some kind of Ichigo and Aizen versus Yhwach fight. If this is the endgame, you want to see a kick *** fight, you want to see them going all out full power. Instead you get reversal from Aizen for like one page worth of anything and the end from aizen. One of the strongest super powers in the series and one of the 5 war powers, and he gets reduced to a one trick special,"Haha I'm not really ichigo"(thats all this hyped up super power villain did to forward the plot).
War powers 5:
Urihara - I would have liked Urihara to have more of an impact against Yhwach's fight. I think his bankai fits him very well, Urihara can take a fight apart and reconstruct it to his own. Much like his Bankai can. Picks things apart and rebuilds it.
Kenpachi - We finally see his Bankai, absolute power, nothing we already didn't expect, almost a berserk mode. So strong his body cant even deal with it without ripping him to pieces. Somewhat fitting, but predictable. Kite Kubo creates this all power character has has to give him weaknesses or he could run with the plot and undermine Ichigo's spotlight.
Aizen - Nearly useless, and feels more like a cameo appearance.
Ichigo - Don't hate me for this, but I feel hes almost entirely useless as well for this arc. All this power, struggles with Askin Nakk Le Vaar but is expected to defeat Ywhach. Tite Kubo, paints Ichigo as brainless most times, like you cant have super strength or power as a main character AND have brains, what kind of message is he sending or other authors as well(ex: Naruto....to an extent Goku). Like Ichigo couldnt figure something out himself, he always finds himself in a helpless situation and if it wasnt for some unknown power awaking inside of him, he would have lost...even more. Now he has everything he can possibly achieve in power, but still loses, cause he cant figure out a way to beat his opponent, but thats more on Tite's way of doing this fight.
Ichibe - Entirely useless, and there just to be there because Royal Guard appearance.
Due to how I personally feel that Tite Kubo's fails at keeping a balance of power levels *consistent* I think it is hard to use any of these power houses in Bleach. Kenpachi, that is a character where Tite is always going to have problems with. His power is already absurdly strong and apparently can continue to get stronger, but even so Tite looks like he has to go out of his way to make sure Kenpachi can never join against the main enemy and even though he has this immense amount of power, his oppenent has to have some kind of hidden Super saiyan 3 trick in power to fight him. The opponent has to have special tricks as to why Kenpachi cant just steamroll him with his power. Opponent's where Ichigo would struggle to beat, but not Kenpachi, yet Ichigo will defeat the next higher opponent.
Commander of the gotei 13. His power is seen to be the best of the best. When you see Kenpachi as one of his captain, you think, well the Commander has to have some serious power. Again, Kite goes out of his way to make sure that a super power gets nullified to allow Ichigo the spotlight to be the one to beat said opponent, in this case, Aizen. Now all criticism aside, Kite did an okay job in keeping the commander down. I don't think after surviving his own blast that could have counted him out of the fight, but again the power level of things is so inconsistent that who knows exactly how strong that blast really was, either way, understandable. However once again, we find the 1000 year war arc, and they basically make the commander useless and throw him out the door fighting against a no body basically, Bankai and all, fight wasnt even worth. Why, because ichigo has to beat Yhwach, because you need to see that he new bad guys are REALLY STRONG and yet the rest of the Gotei 13 is miraculously somewhat 100 times stronger than the commander since they can fight against the new threat some how, OKAY.
Urihara, another power that you have to play around, this guy can change the whole outcome of a fight, without actually having to fight. I think of all super powers, his is the closest to being some what balanced. Kite basically always has him away from the main arc fights, dealing with the rest of the "good guys" offering ways to help them against whatever opponents they are left taking care of. No problem, that's smart in a way, and probably the best way to use someone with his intellect. His appearance and fight in the Aizen arc was fine actually, he did what he had to do and in the end he did more than people thought he did. This gave him the "power" that he has in the series to kick in, while not overshadowing Ichigo's role in defeating everything that comes their way. I actually liked it, I wish there was more, I mean a super power like him, why not give him more fight, but hey, I know, I get it, its for the Ichigo main character plot. The 1000 year war arc, I felt they could have done something similiar but they didn't, maybe I'm being bias as Urihara is my favorite character, but honestly, I don't think they did him any real justice not being in that Yhwach fight, someone who can see the future and change things, YOU REALLY want to throw in some brain power in there and solve that situation instead of poorly handling it the way they did.
Aizen, lets just keep him locked in a chair through the whole arc, done, good job Kite. You blue balled any fan that wanted to see something from Aizen, thinking they would get some epic fight vs Yhwach or 2v1 fight.
Yhwach - can see the future and can change the future, couldn't see the arrow to further the plot to end the arc. The whole Yhwach fight was underwhelming and honestly anti-climatic. Ichigo shows off all his new abiities/powers just for them to be useless, feels just to show for show. Yhwach was all mighty til he took an arrow to the chest and ichigo just swung at him once and thats all there was to that arc.
The sternwitter are absurdly strong for no reason just so that the gotei 13 become absurdly strong out of no where just so that the so called absurdly strong Royal Guard are indeed not strong at all.
TL;DR : Arc felt rushed, more power inconsistencies. Feel like the Aizen arc was the last real arc, at least that fight was really good and lasted a lot versus many characters all coming together to stop one real power.
Also probably rambled too much, sowwie~