Not really, this kind of thinking is exactly what led to the client-side JS framework mess.
Round trips are just fine. Browsers are smart, servers are fast, and HTML compresses well. The site you're reading right now (HN) requires a reload. Stackoverflow requires a reload. Neither are slow to use.
If your page is really that complicated, then I suggest Vue or Preact which are efficient and designed to progressively enhance pages instead of rebuilding everything in JS.
Round trips are just fine. Browsers are smart, servers are fast, and HTML compresses well. The site you're reading right now (HN) requires a reload. Stackoverflow requires a reload. Neither are slow to use.
If your page is really that complicated, then I suggest Vue or Preact which are efficient and designed to progressively enhance pages instead of rebuilding everything in JS.