Yes the developers chose Epic, however, Epic paid them a lump some to do so, Steamworks is a crock because you could still run your game on other platforms even if the steam version had steamworks in it, Steam became the go to place because of a good system, I remember Gamefly, it sucked, This is backwards, consoles are shying away from exclusives and putting there game on PC, and PC's are getting into Exclusives, I for one don't want 50 launchers running in the background on my computer, but what Epic is doing will tell other launcher developers that this is right and it is not pro consumer
You're espousing creative history. Back when it mattered, there were three major services: Steam, Direct2Drive, and Impulse.
Steam had the biggest marketshare because Half-Life 2 and Counterstrike were exclusive to Steam and were far more popular than Demigod, Sins of a Solar Empire and Galactic Civilizations.
One big problem developers ran into was multiplayer connectivity. Developers had to license products like GameSpy (which sucked but worked) or try to develop their own setup (see Stardock's Demigod multiplayer struggles). Valve was one of the first companies to really make MP connectivity bulletproof.
So Steam released Steamworks for free with the caveat that if you used it, you had to install Steam and run Steam to play the game. None of this was really needed to make this functionality work. It was just a way to get Steam onto people's machines and get the Steam launcher to always be running in your system tray.
Impulse didn't require to be running to play your games. Its features worked via DLLs (like most programs). Impulse had more features, refunds (which Steam wouldn't get for years), user reviews (long before Steam), a worldwide CDN for super fast download speeds, built in chat, leader boards, and even gameplay videos. It was, like I said, far far ahead of Steam.
But Steamworks forced developers to distribute the Steam launcher and have it running to play the game. The alternative, Impulse::Reactor did not have this requirement. But Steam wouldn't allow games that used Impulse::Reactor on their store. So developers, having to choose, chose Steam as it had, at the time, a somewhat larger market share and the rest is history.
You don't want launchers running in the background. I agree, I don't either. Impulse didn't require its launcher in the background to run games that used it services (it used DLLs). Steam is what started that.
And no digital distributor is going to sell a game that installs their competitor's store and launcher. That would be insane. And so, little by little, the alternatives disappeared.
Don't take any of this as me being anti-Steam. I'm not. But back when there was viable competition, Steam played rough and they won. They won with exclusive content.
Now, Epic could play hard-ball too if they wanted. They could, for instance, require any game that uses the Unreal engine to install the Epic store and have the Epic launcher running to play an Unreal game. But they're not doing that. They're trying to win developers over with generous advances to address the risk developers are taking and a much, much lower royalty.