At first glance, I thought Steam was in big trouble. Last MAU numbers I could find were 90m for Steam and 75m for Fortnite.

A game store is a marketplace, in startup terminology. Epic already has a lot of the consumer side, and 60% lower fees is a huge incentive for the developer side.

But UX-wise, so many games are built on top of Steam. In Rocket League, you get logged in with your Steam account. You invite friends to party via Steam.

And how would migrating work? Would Epic let me launch the game because I already own it in Steam? Or would I have to re-purchase? (No way people would do that)

If I'm playing on Epic, and my friend is on Steam, would we be able to party?

This introduces a ton of complexity, and while certainly troubling for Steam in the long run (once new games come out), I think their moat is still very strong.

Also 40% of Epic Games is owned by Tencent, so this would mean China's market share of the world's gamer market growing, for better or for worse (depending on your political opinions).