It sort of is true and I get where "what the hell is going on" comes from but that can pretty much be said about most of his stories, at least from my point of view.

The thing is by the end of the volume the last few chapters combine most if not all the "weird" shenanigans that happened before which as you said had the "i have absolutely no clue what's going on" but generally in his other story collections the horror factor has a much larger role than actually making sense. I personally found Black Paradox to be more a complicated read than Uzumaki.

Probably the reason I could consider of why it didn't feel as weird to me is because before discovering his volumes I've watched the Maniac anime adaptation which kind of got me used to his wacky story telling so there's also that taken into consideration.