And he is using the stores to deliver his app, which he is payed for by his donators and Patreon supporters, to them. And I'd argue that his benefit from having the reach of the store is far greater than the stores benefit of having another game there. So it's not like he's not profiting from that relationship as well.
If I wield a vast amount of economic power and you do not, you are therefore obligated to bow to my whims...?
It's not like he's profiting a lot, anyway. This is more akin to a beggar having to fork over 30% of their earnings to a Walmart coz theyre standing outside it. After all, technically the beggar "profits" from doing that.
If he'd complained that 30% is too large of a share, I would be fully on his side. This is unreasonable and I've made that point in the past. But the general principle of getting a share is very reasonable and, just because Google could afford to give him money, they have no moral obligations to do so and change the rules for him because they're so "rich".
It's only profit if you discount the value of his labor to zero.
Google is demanding that every time somebody wants to gift him a cup of coffee to say thank you for giving away something of value for free that they get a cash payment.
This isn't about Google just being rich, it's about Google using their power to extract profit from charity simply because they are economically more powerful.
The app store is also using him to enrich their ecosystem. They allow free apps for a reason even if it does cost them a miniscule amount of money to host them. It draws people to the platform.
The only reason they're willing to sacrifice kicking him off is because they think that they can wring a small amount of extra cash out of him which they can feed to their shareholders.