As the customer, which in a practical sense is the only perspective that matters to me day-to-day, Epic offers me nothing close to what Steam or GOG can give me. Hell, even EA's and Ubisofts launchers were more useful since they at least had exclusives. All Epic has is Fortnite and for someone like myself that doesn't care for that kind of game, there is no reason to even consider their platform for anything.
And given my recent switch away from Windows and to Linux full time on my gaming PC to put a further wedge between me and the things Microsoft has been doing with Windows that I don't like that is a good thing given Epics history of embracing things that will never work as smoothly on Linux as Steam games do with Proton or GOG's native Linux options do.
Yet another thing we have entire books and movie series about what will go wrong, and probably how. Yet somehow a way will be found to make it go wrong in exactly those ways.