another point to consider. Atiyah used to say one direct really understand a proof unless one can prove it five different ways.
Based on this, Navier Stokes or the Hopf problem solution is only the tip of the iceberg. Even if a result is proved, it’s very worthwhile to find a totally different way to prove the result. One that’s conceptually clean and requires the development of new tools. This is something that the mathematical community should value bunch more than it currently does.
So for example a grad student finding a totally new path to a known result is a good thesis.
We may be swamped by ai proved results (although I don’t think this is necessarily guaranteed since the ai proofs seem to gravitate toward proving results in the negative via counter example). However, it’ll be the job of mathematicians to look for conceptually clean proofs that also open up new avenues of research. This may actually increase the need for research mathematicians (basically what Daniel Lott is arguing I think)