> However, imagine a future where even talented mathematicians are nothing but noise in the machine (as is the case in chess now).

Isn't chess more popular than ever? Ai dominating the game didnt seen to matter

Chess is a game where we play and observe for the sheer joy of mastery. Mathematics has some of that “done for its own sake” aspect but not as cleanly. There’s always the chance that some applied mathematics might help something in science or engineering. Whether we care more about process vs outcome is now more important than ever before.

Sure, but if we continue that analogy it does mean that there will be no human contributions to frontier mathematics.

(This doesn't disprove your point because it seems like it should be trivial to make but interestingly)

I don't think there's any computer system which autonomously come up with new directions in openings. As far as I know; a GM looks at stockfish's evaluation of the top x moves and analyzes one that hasn't been played a lot etc.