If done correctly it doesn’t matter. SSR can yield an accessible HTML page and you won’t notice the difference. Client-side JS can adapt the web site to your needs -a personalization that is hard to achieve in static.
I have seen many sites scoring well on various accessibility metrics. There’s no inherent technical limitation of frameworks that would make accessibility impossible, even when dealing with text to speech. We will see many more next year with EAA coming into effect (and many European companies do care about compliance).
Despite regulation I don’t Believe it will actually get implemented even governments have regulations around audio accessibility for education in particular, for years now, and still nothing moves.