@AndersonGarcia You can add a game from the Epic store as a non-Steam game and still use the overlay, etc, so you’re not cutting yourself off. When the game launches on Steam after 12 months, cross-play will also be enabled so it won’t matter if you’re on Steam or Epic once you’re in game.
Please remember that TBS has to finance their game development for at least 3 years before they receive any money from sales if they only launched on Steam. Epic helps the devs by giving some of the money upfront but Valve isn’t willing to do that for small dev teams. A small team working from home or a huge company with multiple games might be OK, but TBS is only large enough to make one game at a time, but still has a studio and almost 30 employees to pay for. Valve makes so much profit, they could offer a similar deal if they cared to match Epic.
Final point, even if you buy certain games on Steam, like the Far Cry series, you still have to use the uPlay launcher anyway - except now you also have to link it to Steam which is even more steps and complications. Epic is just another launcher like battle .net, Origin, uPlay, GOG, etc