https://help.steampowered.com/en/faqs/view/4784-4F2B-1321-800A#:~:text=Steam%20Support%20%3A%3A%20Windows%207%20and%20Windows%208%20Support&text=As%20of%20January%201%202024,on%20those%20versions%20of%20Windows.
"As of January 1 2024, Steam will officially stop supporting the Windows 7, Windows 8 and Windows 8.1 operating systems. After that date, the Steam Client will no longer run on those versions of Windows."
More importantly - "In order to continue running Steam and any games or other products purchased through Steam, users will need to update to a more recent version of Windows."
When you bought your games through Steam did you buy the right for Valve to support every OS forever?
If you install every game you bought through Steam before Steam stops support for your OS you should still be able to run those games through their own EXEs or launchers so yes, you do own the games. What you’re really losing is access to Steam’s store and the ability to install the game from them. Which sucks, but it’s not fair to suggest this impermanence in gaming is something new; physical media didn’t and doesn’t last forever either. Disks get scratched up and cartridges wear out; consoles die and production ends.
For anyone effected by this I would suggest they install every game they own and have a really good backup / restore plan. But even then, eventually no one will make compatible hardware and it will be impossible to find used. After that it’s all about whether virtualization and emulation are good enough for them to be playable. But in the end, sadly, nothing can last forever. So it goes.