skybluerob: Thanks for the replies. I'm not very active on the forum, but you've kind of answered my query, that it's not an isolated issue sadly.
Take into account though that people tend to mix up several different things under this same discussion:
1. Updates to single-player games (or single-player part of games that have also multiplayer).
- Quite often such updates come somewhat later to GOG than e,g, on Steam, and some developers tend to update the game several times on Steam, and at some point release a bigger update to GOG that contains all the previous, missing updates.
2. The GOG version lacking e.g. multiplayer.
- This is a trickier one. Earlier it was kinda expected the GOG version would lack multiplayer (which is Steam-only), but now more and more people feel the GOG version should have the same multiplayer support as the Steam version.
- Then again, even if the GOG version has Galaxy-multiplayer, many feel it is inferior to the Steam multiplayer as there isn't necessarily a possibility to play against Steam users, only other Galaxy users, which usually means a smaller playerbase.
3. The GOG version lacking level editor or access to user-made content
- The usual reason for this seems to be that the developer is relying on Steamworks for the level-editor and the created user-content. Not sure what GOG can really do about this, other than rejecting the game from the GOG store.
4. Lately, many have also started complaining that the GOG version is lacking achievements that the Steam version has.
So, depending how important each of these is to you, the GOG version might seem ok, or wanting, to you. For instance, I personally couldn't care less whether the GOG version has achievements, and for 99% of the games, I don't care for the multiplayer nor user-made content. To someone else they are much more important.
What I don't like though is that now GOG seems to be pulling away some games which lack e.g. multiplayer. I'd still want to buy such games from GOG (as long as they are not too much focused on only multiplayer, in which case I wouldn't probably buy them at all because to me multiplayer games are the synonym for free-to-play, e.g. TeamFortress 2 and Fortnite). I just want the single-player part DRM-free, dammit.
To me the better approach would be that GOG still releases such games, but clearly states that it is lacking multiplayer (or the level editor, or achievements, or the Steam badges). That's what the multiplayer icon is there in the gamecard, after all.