Among the most significant changes with this year’s Elements releases has little to do with new features but instead concerns the ways users purchase and own the software. While prior versions of Photoshop and Premiere Elements have been lifetime licenses — the user buys the software and then owns it indefinitely — this year’s release has moved to a three-year license term.
GOG also lets you download the installers for your games so you can play them with or without GOG. A notable part if their service is the games do not have a GOG drm.
Not sure what you mean by with or without GOG, but their whole thing is that none of their games have DRM.
AFAIK, you end up with identical installs even if you use Galaxy to download and install your games, and the installs will continue to work even if you uninstall Galaxy. The actual game files are exactly the same.
I think the installers boil down to convenient self-decompressing archives for getting the game files onto your machine.
If you have the game files for a GOG game installed using any method, those can be moved around, copied, and run with no problem.
The only reason that I still use galaxy to open the games is because it will upload your saves to their cloud.
Heroic can actually do that too, now.