Sounds like Fedora Flatpak is just trying to do vendor lock in. But they got caught shipping a crappy bug ridden software. Imagine if Microsoft tried to do the same.
The same way liquor store verifies the ages of everyone who buys booze. They don't store the address of everyone who comes in the store. They accept multiple forms of id. No data is being stored. No need to distinguish names because they are just checking validity of the id. No one is forcing the social media companies to store the data. They can do it in real time just like a liquor store verifies the customers.