Hot take from an IT guy: save your important data, make a plain vanilla W11 boot USB (nothing fancy, no Rufus tricks), wipe your hard drive to zeroes, and install W11 like normal. I've reimaged a ton of older PCs and literally never seen it not work. My 10 year old Optiplex, supposedly ineligible for W11, runs W11 just fine.

Microsoft might someday break it, sure. That's not new. Microsoft products were always, in practice, available to us at Microsoft's pleasure. This is the same company that allows massgrave to exist on github because they'd rather we pirate MS Office than allow LibreOffice any oxygen. We'll probably be fine.