You could make the case of “does this have value in the long-term as far as building out a purpose for your online store” which, as far as acquiring timed exclusives go…doesn’t? The younger audience who broadly use Epic’s service and not Steam, probably aren’t the chief demographic for the Metro series. The people who are in that demographic, are probably the ride-or-die Steam users who have shown themselves to be quick towards flaring into outrage.
It’s not like Epic is outright acquiring this developer, or making such a good deal with their service by itself that the developer is throwing up their hands and saying “we’re done with Steam and moving onto the new hotness”. Epic is getting a burst of revenue from the PC crowd who really wanna play Metro 3 right away, and maybe they’ll make a strong enough point of “hey people will just buy your game anyway, and you’ll get the better cut, sooooo maybe stick with us in the future”. But that’s not a guarantee, and this all might just be one bad PR play to entice an audience that wasn’t interested in migrating to their service to begin with.
I don’t believe for a second in the phony arguments by gamers who are catastrophizing about the inconveniences of releases fractured across different services, and at the same time, I don’t believe that Epic throwing their Fortnite money around is what’s going to put a dent in Steam.
(what’s actually going to kill Steam is developers slowly bleeding out of their ecosystem from their flagrant disregard for the growth of smaller studios, which is already happening to such a degree that I don’t think Steam will have nearly the same market dominance in 10 years)