GoGs buisness model is to make games run on current computers, because there is a nieche of people who want to play their old games but can't play them on their new computer.
It's a small amount of people but thanks to the witcher money they seem to do okay for themselves.
I don't think there are more than 5 people in the world who want to play their old game on their old computer, but also don't want to/can't just play their old game but a new digital version of it.