If you signup to social media it will pester you for your email contacts, location and hobbies/interests.
Building a signup wizard to use that information to select a instance would seemto be the best approach.
The contacts would let you know what instance most of your friends are located (e.g. look up email addresses).
Topic specific instance, can provide a hobby/interests selection section.
Lastly the location would let you choose a country specific general instance.
It would help push decentralisation but instead of providing choice your asking questions the user is used to being asked.
Basically Epic like every other publisher has created their own launcher/store.
They aren't trying to compete on features and instead using profits from their franchise to buy market share (e.g. buying store exclusives).
The tone and strategy often comes off as aggressive and hostile.
For example Valve was concerned Microsoft were going to leverage their store to kill Steam. Valve has invested alot in adding windows operability to Linux and ensuring Linux is a good gaming platform. To them this is the hedge against agressive Microsoft business practices.
The Epic CEO thinks Windows is the only operating system and actively prevents Linux support and revoked Linux support from properties they bought.
As a linux user, Valve will keep getting my money and I literally can't give it to Epic because they don't want it.