So the only game store I currently buy games from is Steam. Barring Humble Bundles which I sometimes buy but usually always redeem on Steam.
Although over the years I have accumulated sizable libraries of games in all the stores I never bought from like GOG, Uplay, and Origins via various giveaways. Epic Games will share the same fate. I have no real intentions of ever buying games from there, but I will gladly take stuff that is as cheap as free.
If there is a glorious store front slaughter in the grimdark future armageddon of the apocalypse, my bet is on Steam making it out alive. #Impulse-fooled-me-once
As a side note, the games in other game store libraries I actually rarely basically never really play. It is more of a collectors habit. Those games exist in a 2nd class backlog behind my Steam library backlog. :)