Probably waiting to stop once their store hits a critical mass and repeat business

Guessing that never happened and never will

Steam has great prices, great sales, great features for the users

GOG has a decent selection, is good with older games, and no DRM. That's still an advantage

Epic has....an ability to make you have to log in or update constantly? I don't see the advantage over anything. I personally refuse to give them money for taking away store choice with exclusives