Dumb question but Apple’s apps are buttery smooth. I just assumed they were using swift and not a web stack to render their UI. Am I completely wrong?!
(Except maybe the "Home"/"For Me" pages which are just "discovery page" extensions of the store and the Apple Music service that's built on top of it)
The macOS one descends from iTunes and the iOS one descends from the original iPhone which sure as hell wasn't a webview.
There's also some parts of System Settings that were always web views, which I always found surprising for a company trying to make the case for native apps.