When the user triggers a change of the underlying data, I do a roundtrip to the server and re-render the current page. I keep the time needed to do so under a second. My users regularely express how WOWed they are by the snappyness of my sites.
I guess what other sites save on re-rendering html, they lose multiple times on bloated code.
„Under a second“ might be ok for websites, but doesn’t cut the mustard for web applications. People expect highly dynamic user interfaces which react almost instantaneously.
That literally means that you aren't doing SPAs. If you aren't doing SPA then yes using React or Vue is rather a waste.
However the majority of sites these days use some form of SPAs.
Also under a second is a very low bar to strive to. a fast round trip to the server is 100ms. A reasonable one is somewhere around 300ms. Displaying effects to changes is often under a millisecond in SPAs and is basically impossible to reach in Multi page applications.
I'm not saying that React/Vue aren't important and drastically changing what's thought of as best-practices in web development... but just because everyone on HN uses a front-end framework for their websites doesn't mean "all websites" do it.
I guess what other sites save on re-rendering html, they lose multiple times on bloated code.