I find the anthropomorphic children's cartoon aesthetic of furries to be extremely cringe. Its juvenile and ugly, and then when its sexualized or people are making fursuits, it becomes exponentially more cringe.
I think if furries had a better art style and less weirdly anthropomorphized, I might even be on board.
That's a good question. Some anime styles, definitely not. Other anime styles, maybe. But it definitely doesn't feel "childish" to me in the same way anthropomorphic animals do. It may be my personal experience. I associate anthropomorphic animals, and the particular art style of furries, to media I consumed between the ages of like 2 and 8. I wasn't exposed to anime until I was a young teenager, so it doesn't really have that association with childhood for me.
I really do find it fascinating to analyze these biases, because I do consider it an irrational bias that I have. I can analyze the reasons for it, but it isn't really a logic, just a feeling.