Apple has fallen into the same trap that Microsoft has -- changing their UI not to advance the state of the art, but just for the sake of changing it so they have something new to sell.
This comment makes no sense. Apple hasn't fundamentally changed the UI on iOS or OSX since the initial releases apart from say the iOS look & feel refresh and gestures to support iPhone X. And in the last few releases there have been almost no UI changes. It's actually one of the disappointments of the Apple platforms.
It would be a disappointment if I had to relearn a UI I've been using over a decade just because I upgraded my software. I don't have time for that. Go get your crazy wizbang UI interfaces on Linux. There are plenty there.