they optimized for current hardware, sacrificing some performance on outdated hardware.

I'd rather windows uses my SSD to the fullest, than that it makes concessions to spinning disks.

How is Windows using SSD to its fullest? All it seems to be doing is taking advantage of the greater speed to perform more I/O that it didn't do before which negates any performance improvements the SSD brings.

I'm not sure this is the right take, as I don't believe it's a matter of choosing to optimize for SSD vs. HDD's. Disks got faster, so the bar for baseline acceptable performance got higher.

It needs a SSD drive to boot faster. Otherwise it takes a few minutes instead of seconds.

Windows 10 is for newer hardware anyway, it runs slow on older hardware.

You are completely missing their point. "For newer hardware" means slower. I remember how Windows 7 was so well-designed that it actually ran faster on my all of my old XP machines than XP did. It was a step up in performance, not a step down.

In 2018 Microsoft disbanded the Windows team and moved engineering efforts to its cloud and AI teams. Windows 10 is on life support by engineers who aren't intimately familiar with its codebase. Performance and usability will only degrade in this situation and the specifications of newer hardware don't excuse constant deterioration in performance.

It was a re-org, those engineering teams just moved to be under CAI or ED. The people are still there.

The people are still there, but there's no organizational impetus to always use them, plus they have other duties now. The team being disbanded means a loss in product tightness and quality control.

That doesn't make any sense to me. Are you saying you work on one of these teams?

All non Azure MS products are legacy now.

Windows 10 is probably slow on HDDs because it's updating a load of UWP apps in the background, resmon.exe disk tab will show what's going on.

Ironically, Mark Russinovich, the author of Regmon, is now responsible for Azure