All the ones I can think of are for individual games rather than general launchers lol. And third party mod launchers that you have to add your own games obtained elsewhere :p

For me steam input the big one that pulls me towards steam; seamless proton integration too, but that one I could handle losing, steam input on the other hand I think is one of the best input remappers out there, I even added all my non-steam games to steam to make use of it too haha