The only way to access Spiderman 2 on PS5 is either through a disc, or Sony's servers and encrypted on the PS5 storage, impossible to backup or restore.
Spiderman 2 on Steam is actual files on your hard drive you can back up, copy anywhere, then you're a single Steamless or Goldberg away from being able to play your purchased game at any time, stripped of its DRM. And if Steam truly decides to fuck you over and delete all the copies of your game, they're still on thepiratebay.
Steam isn't a miracle child, and is to be distrusted just as much as any other company. It just happens to be on a platform where they can't fuck you over quite as hard.