I don’t feel quite as negatively as you but pretty much the same otherwise. I’m actually kind of surprised that Luffy, sanji and Zoro have such enthusiastic fans because I frankly don’t care about any of them. Chapters that don’t involve them tend to be much more interesting. The WG, the marines , the revolutionaries. The scabbards have been dull. Bm and Kaido have been dull, and both cartoonishly evil and incompetent simultaneously. Which is fine, it is a cartoon, but they don’t stack up to other op villains, almost all of which are a lot more complex.
I don’t think it’s just us. If you take a random stretch of 70 chapters pre-ts, in most cases you’ll find dramatically more character growth for the protagonists, world building, and compelling conflict against a compelling villain than in these past 70.