Titanium: But, again, this is years away from being practical to implement or cost effective.
Once you setup an emulator to work on a certain kind of PC with a certain kind of game, and get it flawless, you are cooking with gas for all other matching PCs and games. So one for all rather than doing it for each game or PC.
As you can probably imagine, software (inc. games) developers don't buy every PC hardware combination out there, so at best they kind of emulate won't they don't have access to. So it is not surprising that they don't always get it right, and many gamers of course don't play their games on a Gaming PC or Gaming Laptop, but have a fairly standard one, albeit maybe with lots of grunt. Most people tend to go multi-purpose, which is not always the best for gaming, some games especially.
As can be seen here in the forum, many gamers have issues with a game, and tend to blame GOG, while plenty of others don't have any issue with that same game on that same OS. So the difference really is the PC and settings on the PC or drivers etc. If anyone is to blame, it is the developer usually, though catering for every PC hardware combo out of the box, is perhaps a tough ask ... and so can require trial and error to solve once an issue arises.