is it possible to lose the de jure right to install the game in that way due to licensing issues on GOG’s end
Someone can correct me if I’m wrong, but my understanding is that no, you can’t. When you buy the game, you’ve obtained a perpetual license to install and play that game, similar to what you’d have if you bought the game on a disk. You can lose your ability to download the game, that isn’t guaranteed to be unlimited or perpetual, but installing it via the installer you downloaded, and playing it once you do, are forever. (This is in contrast to something like Steam, where you rely on their servers granting you permission to install the game, and that permission can be revoked.)
How is backing up an installer from GoG different in any way to backup a game folder in Steam?
Both can be copied to a different computer and used to run the game offline forever (unless of course the game has DRM, in which case both suffer from the same problem).
Correct me if I’m wrong, but don’t most Steam games require the steam client in order to run? You can’t necessarily just copy the files into a flash drive and deliver them to another computer.
(unless of course the game has DRM, in which case both suffer from the same problem)
That’s GOG’s whole schtick, none of the games they sell have DRM when purchased from their store. You can always copy the installer to another computer and run it.
I don’t think there’s a way of checking how many games are like this, but I find that the majority of games I’ve tried doing that just work, and the ones that don’t are mostly bad programming (e.g. crashes trying to load the steam library).
That’s GOG’s whole schtick, none of the games they sell have DRM when purchased from their store. You can always copy the installer to another computer and run it.
That’s not entirely true, as a general rule I think GoG has a lot less DRM-ed games, but it’s not 100% DRM free like they sometimes claim https://www.gog.com/forum/general/drm_on_gog_list_of_singleplayer_games_with_drm/page1