Steam’s backend/API works much better out of the box than Epic’s. Which means, multiplayer games on Steam are often more stable/less buggy compared to Epic. For example, Chivalry 2 (Epic exclusive) took months to get their party system working, while Mordhau’s (a similar title on Steam) worked straight out of the gate.
https://www.reddit.com/r/pcgaming/comments/sery2x/why_should_i_buy_on_steam_rather_than_epic/

