Steam offline still requires you to connect to the server to launch the game for verification, after that you can play offline. Hence, steam itself is the DRM.
I can, however, download the game files to my side from GoG. Take them where I want, when I want, install them without internet nor the need to connect to any kind of digital platform first before playing them offline.
I never said physical copies would last forever. I also never said all physical copies are still functional. It's not my fault you inferred that.
I personally have physical media from the mid/late 90s that still works. Such as my disc for Thief: The Dark Project, Star Wars: Episode I – The Phantom Menace, Quake, Quake 2 and so on. I've done myself a personal service and created .iso of these discs. I've even got them running on my Windows 10 system. Should I need to, I could get a VM of XP going and run them from there and I wouldn't require a bunch of work arounds. As the years moved on there were more and more online server connection requirements for game keys, but they can be circumvented. When physical copies started requiring Steam for verification, that was the downfall of physical media; sure you could buy a physical copy of a game, but if you didn't agree to linking it to Steam the game wouldn't run. So now you have a physical copy that requires digital gaming platform (just another type of DRM) to run.
I do have a few physical games that I just cannot run under Windows 10 because MS removed the ability to allow disc DRM such as SecuRom to run on any Windows version since Vista. Can't install the game files from disc sadly, you need a cracked version of the game then.
