I just upgraded to Windows 10 21H2 last week, after upgrading to 21H1 a couple weeks ago. I'm looking at my C:\ drive with hidden files viewable and there is no "Users.old" or "Windows.old" folders.
This is on Windows 10 Pro using my personal Microsoft account, but the PC is managed through Intune so I can access corporate resources.
What I'm saying is, to use your own words, "you're objectively incorrect."