You might be able to attract new players that don’t have any baggage, but older ones with games on Steam, you’ll need to climb the Everest to convince them.

At this point, my Epic library is technically bigger than my Steam library, even with family sharing somehow? But its a bunch of free games I don't care about, except for a few, and steam has modding features built right in, so one of the few games I have played after getting it free on Epic, I eventually bought on steam when it went on sale there. There's also the history of achievements and friends (and sharing of games with those in my steam family). So if I had to pick between Steam and Epic for a game, I'd pay more for it to be on steam. Still, I'd rather go with GOG or itch if I didn't still have steam credit from gift cards.