> Windows 98 was at the same time but the MacOS interface has changed a lot less than Windows has.

That's only because Windows had to dial things back a lot after Windows Vista. Incidentally, Vista UI was also glass-inspired. Hmm.

Windows 8 "Metro" interface was different in its own way too, I suspect if Microsoft's mobile efforts had been more successful[1], Metro's design influences would have a much bigger sway over today's Windows desktop.

1. i.e. had they became the number 2 or 3 phone OS, and sold tablets with volumes comparable to the iPad. Touchscreen-isms would have inevitably crept back to the desktop OS.

Weirdly even the old System versions of Apple OSes don't look as dated as Windows 98 - probably because of the the document vs application paradigm.

MacOS basically looked this way up to the mid 2010s.