They also were unnecessary even before AI, the biggest advantage of React over HTMX-style apps was that you could recruit someone more easily but the SPA complexity wasn't worth it and it scaled terribly.
Now that you don't write the code now, I don't see why I would pick React style libraries unless the codebase is already there.
We just write different stuff. For content driven websites you can skip js frameworks altogether. For web apps it would not be a good idea.
It's all about how much interactivity you need. A lot of business web apps are full featured commercial software packed in SPA form. You will need a lot of stuff client side and without framework it will be a mess. Unless you write framework yourself but the you are reinventing a wheel.