If you want to guarantee that you can backup your PC games and run them without a client, then there is always https://www.gog.com/
I wish NFTs had taken off as a system for managing decentralized transferrable digital purchases instead of being another investment scam.
My entire Steam library is backed up to LTO tapes. I can get most everything running without needing Steam.
I will continue to support this business model, because I retain the power to own the system and the data.
I thought most Steam games relied on remote activation/verification? Can you install and run them on a non-networked machine? If not, your LTO tapes are close to worthless because Valve (or its buyer) can still pull the same trick that Sony did here, with the same effect.
If you have invested into Sony platforms and games, you're stuck. You either write it off and move now, buying hardware during a component crisis, or you keep investing moving forward. On a PC, I might lose access to games on Steam but my hardware will allow me to buy new games on a different storefront.