> every application I’ve worked on is quite a bit bigger than the framework itself

That's why most client-side routing libraries support lazy loading. You don't have to load the entire application at once, only the parts you need.

> So you need to download the app, maybe have that app perform some fetch requests

That's... completely unrelated to React, though? Parent comment claimed that React is slow and HTMX fast - does HTMX make fetches magically faster or what?