Norglics: Well It is it's first year. I compared it to GoG , I think Epic is already larger than gog.
Depends. From my perspective Epic is much more competing with Steam than with GOG, and potentionally affecting common Steam users' purchasing decisions more than GOG users'.
Just speaking of myself only, but why am I on GOG, and not (only) on e.g. Steam or Epic? Mainly these reasons, in this order:
1.
Officially DRM-free games. Not just "well, some games might be DRM-free, but you never know for sure and they are not supported as DRM-free games without a client" like on Epic or Steam or EA Origin. Officially.
2. The games offered as coherently maintained (DRM-free) standalone installers (so it is not like on Epic or Steam where I have to download
and install the game first with a client, and then zip it to my archive; or like Humble Store where only some of the games have standalone installers, and HS doesn't maintain them in any way but different games have totally different installer formats, file naming schemes etc., whatever the game publisher decided to provide to HS, I much prefer how GOG game installers have an uniform format and naming.).
3. The ability to massdownload all my games to my local archive easily, and keep them up-to-date too without manual tracking. This it not thanks to GOG.com itself, but third-party tools like gogrepo and lgogdownloader. I am not aware of similar tools for Epic or Steam; I recall hearing that Humble Store might have something similar (unofficial), not sure if it is maintained anymore.
4. The classic games. Was e.g. Warlords 1-3, Diablo + Hellfire or Warcraft 1-2 released also on Epic?
Now, you could argue that most GOG customers don't care about those... but that makes me wonder, why are they on GOG in the first place then, and not just Steam? What made them decide to buy some games from GOG instead of e.g. Steam, if not for at least some of those reasons?
I mentioned earlier that me acquiring e.g. Superhot for free from the Epic store lessened my interest to buy it elsewhere, and I am likely to buy it only for a deep discount. But the thing is, due to reasons #1, #2 and #3 above, it would still be GOG where I'd buy it, not Steam or Epic or EA Origin.