BreOl72: Leaving out for a moment the fact, that these two games
(TW3, CP2077) have nothing in common with "Hitman 2016"
(which has most of his SP gameplay hidden behind always-online-DRM), I will try and answer your question:
Hitman GOTY, Witcher 3, and Cyberpunk 2077 all
do indeed have something in common: namely, they all have/had singleplayer content gated behind DRM-gates.
SpikedWallMan: Otherwise, Galaxy should just be downscaled to be a very simple offline installer downloader/launcher just for GOG games
Indeed it should; however, GOG need not do any major work to make that "downscaling" happen. All they have to do is to abolish Galaxy 2.0 and reinstate Galaxy 1.2 in its place, Galaxy 1.2 which is vastly better than Galaxy 2.0 is anyway, and also Galaxy 1.2 has a much more functional interface, and also none of the aggravating bloat that Galaxy 2.0 has (i.e. very annoying ads for "games that other people are playing").
Abolishing Galaxy 2.0 and replacing it with Galaxy 1.2 would be a very simple & cost effective thing for GOG to implement, and doing so would make GOG a lot better too.