Yes, unfortunately Mastodon 4.0's public web interface now uses JS to render threads. Lots of people are mad about it.
The entire premise is absurd. What application spends more time on SSR than data fetch, or other? Exactly freaking zero that ive ever operated.
Fwiw, I'd like this site to have fallbacks for non-JS users, but it's a heck of a lot of work to make everything twice and nobody asked yet or contributed a patch for even basic functionality