One feature that's kind of difficult to emulate without Javascript is the ability to play media continuously while navigating with the back and forward buttons. Rich Harris talked about this at the 5 minute mark of his video on whether or not SPAs have ruined the web [1].
Youtube actually uses this capability specifically. If you add a Youtube video to a queue, it switches to a picture in picture mode where you can navigate while the video is still playing.
The only other technical challenge is handling animations between route changes. There's a browser api in progress (the shared element transition API) [2], that will allow animations during navigations without client side routing, but it still requires Javascript. Navigation animations are arguably just purely aesthetic though.
Youtube actually uses this capability specifically. If you add a Youtube video to a queue, it switches to a picture in picture mode where you can navigate while the video is still playing.
The only other technical challenge is handling animations between route changes. There's a browser api in progress (the shared element transition API) [2], that will allow animations during navigations without client side routing, but it still requires Javascript. Navigation animations are arguably just purely aesthetic though.
[1] https://youtu.be/860d8usGC0o?t=299
[2] https://developer.chrome.com/blog/shared-element-transitions...