> Older UIs were built on solid research. They had a ton of subtle UX behaviors that users didn't notice were there, but helped in minor ways. Modern UIs have a tendency to throw out previous learning and to be fashion-first.

Yes. For example, Chrome literally just broke middle-click paste in this box when I was responding. It sets the primary selection to copy, but fails to use it when pasting.

Middle click to open in new tab is also reliably flaky.

I really miss the UI consistency of the 90s and early 2000s.