EGS giving away Subnautica was a genius move IMO. It was the Killer App - for me anyways, that got me to use the platform. It's easily my favourite game I've played in 2018/19. I've never used Origins - just not as impressed by EA's offerings since Mass Effect 3. I also do not use UPlay - I figure if it's available on Steam I'll just wait for a sale from Steam or one of the major key resellers.
One of the reasons I'm reluctant to move off of Steam is the fact that I've been a user since it was released in 2003 and I've gotten crafty with getting discounts and free games. I usually am able to cop a free game or two just from re-selling cards during one of the major sale events. Aside from Steam and GOG which fills a different niche of old games, I'm not really interested in using other platforms and I haven't noticed a discernible dip in quality of life by not having EA Games in my life.
Epic Games Store successfully roped me in with their free offerings and they've kept me in with their exclusives. I've already bought Subnautica's Sub Zero Expansion, Detroit: Become Human, Ashen, Journey and Outer Wilds from them due to their sales event. I know this probably sounds like a shill, but I've been pretty happy with the store. There's a couple of minor inconveniences with the interface (No shopping cart? Really?) but overall, I can't see why the internet hates it so much.