That's the issue.. every new OS has brought some features or stability improvements that are huge upgrades over the older OS.
WSL 2 is a must-have for me now, so Windows 10/11 is much better than anything that came before in that way. I may be alone in this, but I actually think Windows 11 has the best design of any Windows so far. The problem as usual, is that they haven't made the entire OS consistent. I wouldn't mind the new control panel if you could actually change every setting in windows in that one control panel.. and not have to dig through to find control panels that still date back to Win2k. And the new/old context menu in explorer is an absolute disaster. Then new design is fine.. but how the hell did they manage to not make it support all the options of the old context menu?
There’s a way to remove it, of course, by running some obtuse console command. But normal people have no idea how to do stuff like that.
If you could get winterm on it and recent Firefox it’d be quite usable. Perhaps ReactOS one day.
Windows 7 with classic UI is probably the most-recent decent version.