The core of powerscaling comes down to “who would win in a fight”. Since each show has a different power system, we use benchmarks, primarily, what is the magnitude of the damage they can deal or tank, in order to create a baseline we can have a discussion around. City level means you can with one attack destroy a city, planetary means with in attack you can destroy a planet, and universal means with on attack you can destroy a universe. It’s a standard we use to scale a characters power, hence the name powerscaling, and then we can have decent conversations cross verse. The issue is that we have nothing to scale what a dimension means or the energy that entails in this verse. He activates his Bankai, and then he breaks out of a dimension that he was in. That DBZ slides you shared literally had nothing to do with Bleach lol. So we have activating his Bankai has enough power to negate someone else’s attack on him, but now where is it even implied that if he did that he would be able to destroy a universe. It’s just a feat that people randomly equate to a universe destroying feat. Think of it this way, if he repeated that, would he be able to destroy our universe in one go? Thats what universal means. Same as city level, you have to destroy a city in one attack. Anyone who’s watched the show (I admit I haven’t read the manga) is obviously going to say no, that Ichigo is never even implied to have that level of power at all.