I use syncthing for my emulator savestates between retroarch on my deck and retroarch on my android tv(no steam client or steam cloud sync for android or android tv), no matter where i decide to play I always have my most recent save. It also has versioning so i can go back to older versions of saves. I use a virtual private server(or seedbox) running syncthing as the in-between cloud host.
I wrote up a guide on how to do it in the Steam Retroarch community guides. It shouldn’t be much different for PC game saves, just choosing a different folder, specifically the one with your chosen files.