Windows 3's design was a first shot.

Windows 95 was extremely polished and well done.

Windows XP was a response to PCs becoming mainstream and figuring what the everyman wanted was more flair and fashion.

Windows 7 was a response to desktop Linux (Compiz et al.) capturing people's imaginations.

Windows 8 was a response to iOS while trying to avoid Apple's skeuomorphism patents (fortunately).

Windows 10 was realizing that none of that really mattered, they already have all the users anyway, so they just need long-term UI stability now.

I hope Compiz et al didn't inspire anyone, the low point of linux UIs (and that is saying plenty!).

Thankfully Microsoft showed restraint. Windows Vista got a GPU accelerated 3D workspace but the only real showcase for it was the very gimmicky and useless win+tab feature.

For me the savior of Linux is the niche tiling window managers.

Personally I'd go back to the Windows 95 era and use that as a starting point for a new, consistent, predictable, ergonomic, universal, and aesthetic GUI framework. I don't think any of what we have today is the ideal.

Take a look at this iOS critique https://uxcritique.tumblr.com/

To me Windows XP’s look & feel was among the best. Except for the fat Window title bar.

XP was playschool. Eww. Windows 2k was great however.

Maybe I just don't remember enough about Windows 8, but how is Windows 10 that much worse, in your opinion? I feel like it's the exact same as 8 sans the Metro Start section and a few minor (in my opinion) UI tweaks.