I don't understand the draw of Steam. I have it and own a couple of games, but I don't like it and rarely play. This may well be the deciding factor that makes me pass on BaB.
I certainly appreciate the simplicity of just downloading a game and done, without requiring another program lurking in the background to run it. On the other hand, I've also noticed some developers like Paradox or Frontier effectively have their own launcher overlays doing a similar thing anyway, even without going through Steam.
However, all in all, I like Steam. I play a broad range of games, some which are hard to access digitally without it. It is extremely convenient to find stuff, purchase, install, update. I originally had the CO2 download direct from LnL, but switched to the Steam installation when I got a new laptop for that reason. Some devs/publishers also seem to like it for having a lot of developer/publisher support, and it's quite possibly easier and cheaper for devs / publishers to outsource digital distribution to Steam than run their own.
I've used a few other digital distributors (e.g. Activision/Blizzard, Epic Games, I think Ubisoft had one for a while and maybe still does) to play the odd thing, and broadly, they suck compared to Steam and I view them as deal-breakers for anything but the biggest must-haves.