https://www.gamingonlinux.com/2024/05/netris-is-an-open-source-cloud-gaming-platform-with-stadia-like-features-using-proton/
If you're a fan of cloud gaming, you may want to take a little look into Netris. The developers say it's a GeForce NOW alternative, one you can self-host with it being open source. They're also keen to highlight some Stadia-like elements of it too.
Publishers will like a database because it can be modified. If they were forced to implement such a system (thus abandoning all 'sell the same game to the same person twice' for different platforms), they'd oppose a blockchain system hard, since it would make it pricier to:
a) publish seven bazillion versions of any given game
b) revoke ownership of games just because it's cheaper to do that than honor the deal they made with customers
c) correct any data-fuckups they will inevitably make because they went for the cheapest route possible to implement this, and it went pear-shaped from day 3 onwards
I'm very much on the database-side here as well. I work for a Telco company here in Germany, and we use several such databases that are regulated by external bodies and government agencies to communicate between carriers (for number porting and such). Works great overall.