"Let's throw every away and start from scratch" is a tempting idea, but it rarely works. Even taking your example of panes, windows, tabs, apps, and spaces, each of those have a separate and identifiable use case that, IMO, is valid. At least in my mind, I have a mental model around where panes, windows, tabs, and apps are appropriate, and I personally rarely use spaces (though I certainly understand people who like them), and they've never bother me because I can safely ignore them.

And when you look at the issues identified in the article, they all seem very fixable to me. Fixable starting with Apple getting new design leadership, and given the guy responsible for Liquid Glass jumped to Meta, sounds like it was a good thing for Apple.