You can’t compare the UI of a web page built in this way to an SPA or a native client. Re-rendering an entire page on every interaction is strategically never going to get you the same experience. I understand wanting to be a browser purist, but web applications have had pretty laughable UX compared to native apps of even 20 years ago.

I mean look at an iOS app designed by Apple. I always reference the AppStore app itself. You simply can’t build that app as a web app, certainly not by using iframes as a “solution.”