https://alexmeub.com/old-windows-icons/
In my opinion, the UI design of Windows peaked in the late 1990s. The classic, utilitarian icons from Windows 98 just look amazing.
Totally agree on 8 and even 11 appears to be busy despite their intent for the contrary. That being said I feel like 10 will go down in history with XP and 7 as being simple and usable. I could have blinders on though because I've been using it for like a decade now.
10 was definitely the best version of Windows in a long time but personally I'd still put it closer to 8 and 11 than XP or 7, it's got far more advertising, telemetry, awkward inconsistency, and is more locked down/less customisable.