The Steam release, so I can play it without supporting a company notorious for hurting PC gaming. (Epic)
I have mixed feelings about them, personally. Epic Games created my favorite game of all time, the original Unreal Tournament (1999) but failed to understand what they had created (an athletic-like online multiplayer cybersport and not just a disposable game) and lost its franchise by changing the game play in the sequels. If they had done what UT99 fans had wanted and just faithfully replicated the tried-and-proven game play but with new game modes, improved netcoding, better graphics, and improved online multiplayer functionality we might be playing UT99-8 or UT 2021 today instead of the franchise having died out with the release of the consolized (if not outright console port) UT3.
(Sins-2 Devs...are you reading this? Don't let what happened to the UT99 sequels be what happens to Sins-2. Don't outsmart yourselves and stray too far from the tried-and-proven game play formula you had with Sins Rebellion. "But...but we can't make the same game with prettier graphics!" Oh Yes...Yes you can. Maintain the winning formula of the game play Sins-1 fans loved but maybe add some other features like a new race, new planet types, new orbital structures, 2nd or 3rd starbase options, 2nd or 3rd titan options, or expand the tech tree, and dramatically improve the online multiplayer functionality. Also, remember, if Sins-2 is a success and is marketed properly the majority of Sins-2 purchasers will have never played Sins-1, so the original game recreated in a new engine will still be new to them.)
My connection to the UT games is the reason why I ever installed the Epic Games launcher. I wanted to get my hands on the developing Unreal Tournament 4 which was released and playable as a "pre-alpha" and ended up abandoned when the Devs left the project to get rich making Fortnite Battle Royale. I don't fault them for wanting to make some money, but it would have been nice if they could have taken 0.001% of the Fortnite profits and used it to go back and finish UT4.
On the plus side, they do make Unreal Engine available to developers and enthusiasts for free and give away free games, some of which are AAA titles. I've "purchased" dozens of them for $0 but have only played a few.
I'm OK with getting Sins-2 on the Epic Games Store, but I'm going to feel badly if it turns out that the patches, DLC, mods, and custom maps end up running through Steam a few years from now and I have to repurchase it to keep the game up to date and play online multiplayer (or if the Epic Games Store simply goes belly-up and I have to repurchase it on Steam.) Some sort of "guarantee" that that won't happen or that if it were to happen that Steam keys would be issued to Epic buyers in such an event would make this easier.