This is not at all what mathematitians are saying. They say LLMs obfuscate proofs even more. Saying that mathematitians obscure proofs is nonsense. Maths requieres a big effort from the brain to be deobfuscated as you say, and deobfuscating maths requires understanding, which takes even longer. Thats why textbooks dont exist just after a new proof appears, it takes some time to digest it and identify the key parts.

Maths is a language, and learning a language takes time. Its like if I say that japanese made an effort to obfuscate their language just because i cannot read it or read it as fast as english.

LLMs are autimating some part of maths which is formal manipulation. It happens that computers are much better than humans at formal manipulation. In the same way that computers are much better at mathematical computations. That is the huge change in the field. But any working mathematitian can tell you that formal manipulation is just part of the research job.

The powerfull thing about maths is that formal manipulation has allowed humans to go further "for free": you just need to understand the foundations, and the formal system allows you to compute new results for free without needing to reunderstand them.