...facts don't back your information...at all:
http://www.gpw.pl/karta_spolki_en/PLOPTTC00011/#chart
Publishers gobble up some 80-90% of game profits. CD Projekt self-publishes as well as publishing for other developers at rates that are competitive with, if not beats Steam. They're also constantly making money from GOG which costs them next to nothing to run. CD Projekt has a business model that is doing extremely well.
Witcher 3 coming out soon is going to cause another surge in their market price and finances. We already know they are pumping that money into two coming titles ("They" and "Cyberpunk 2077") as well as GOG Galaxy.
I buy games from GOG whenever possible because it is the model for the future. This refusal to trust people that has been perpetrated by the software, game, film, and music industries needs to end and they're the only one so far that are serious about doing it.
I think GOG is here to stay. The question is whether or not AAA publishers get on board. The only way they will is if they perceive themselves as losing money because they aren't on GOG. Don't get me wrong, AAA publishers have put a lot of older titles on GOG but to go from publishing old games to publishing new releases on GOG, that's what I'm looking for.