The options are there, though. It is a restriction of knowledge rather than a walled platform sense.
I am certain that people who can install mods from Nexus for Bethesda games/Cyberpunk 2077 have the technical ability to install games from GOG, Epic, or other sources (just look at the Java Minecraft and Vintage Story communities).
I hate to break it to you, the majority of PC owners don’t either. PC hasn’t been a majority power-user platform for a long, long time.
The options are there, though. It is a restriction of knowledge rather than a walled platform sense.
I am certain that people who can install mods from Nexus for Bethesda games/Cyberpunk 2077 have the technical ability to install games from GOG, Epic, or other sources (just look at the Java Minecraft and Vintage Story communities).