I was a cheerleader for 3d world for a little while too, mainly just cus I was hyped for another 3d mario. But then I played it and it was a meh as it gets.
Yeah the environments were getting so stale, just felt like they were churning out the same by-numbers stuff over and over.
It seemed like with odyssey that they purposely went out of their way to make environments that put twists on the typical thing you expect. Like one of the first worlds you go to is a desert world, but it's a *cold* desert. And one of the later levels is technically a lava level but it's framed as a cooking-themed level so what would be lava in a more boring mario game is now boiling stew. Much of it looks cartoony, but much of it also doesn't. There's a dinosaur in the first level that's practically photo-realistic and it fits in as well as anything else does.