No one would care if Google banning a developer meant they could list their app through a non-Play app store with decent exposure, or a non-App Store at all.
But that's not the reality we live in.
So it's more like if Walmart moved into my podunk town, put all the local shops out of business, and then banned me.
Maybe Google kicked this guy out for the same reason they fired off their own Stadia devs.
* Except in China, in which case it's only true for their domestic Android market