It can't be that cheap to maintain an app like Origin or UPlay and all the associated infrastructure, etc..
Scammers are not an easy cost to estimate or an easy value to sell resistance against.
^1: I doubt reviews are ever coming since it would mean bad games would get fewer sales; Imagine how many more sales Cyberpunk 2077 has gotten on the Epic store as no potential buyer sees the negative reviews for the game.
The only people I know using it as a broad Steam replacement are doing so ideologically: they want a competitor to exist so they use it even if it's worse.
And for others it has meant that the Linux version was delayed until after the excusivity deal was over (e.g. Metro Exodus) or removed (Rocket League).
There's not much software that supports Macs, but there's increasingly little on Steam too that runs on a modern version of MacOS too because of Apple's decision to abandon the space.