So in other words, no, since it’s impossible for a Steam game to be DRM-free. Some have less DRM than others, but unless they let you download an installer that you can use without connecting to their servers then there’s still DRM.
For those games, you can literally just make a copy of the game directory after downloading it, and back it up somewhere. Just run the game EXE (or equivalent on Linux) to run it, even on a system that doesn’t have Steam installed. Everything you need is in there. That’s all Steam is doing when you ‘install’ a game - downloading its files and extracting them. It also installs any required runtimes like MSVC or .NET, but you can do that yourself too.
Of course, the best idea is still to buy games on GOG instead.
Not unless it’s DRM-free. You don’t own games that have DRM. You just have a license to use them, which can be revoked at any time.
So in other words, no, since it’s impossible for a Steam game to be DRM-free. Some have less DRM than others, but unless they let you download an installer that you can use without connecting to their servers then there’s still DRM.
It’s definitely possible for Steam games to be DRM-free, especially older ones. https://www.pcgamingwiki.com/wiki/The_big_list_of_DRM-free_games_on_Steam
For those games, you can literally just make a copy of the game directory after downloading it, and back it up somewhere. Just run the game EXE (or equivalent on Linux) to run it, even on a system that doesn’t have Steam installed. Everything you need is in there. That’s all Steam is doing when you ‘install’ a game - downloading its files and extracting them. It also installs any required runtimes like MSVC or .NET, but you can do that yourself too.
Of course, the best idea is still to buy games on GOG instead.