Hello, hello everyone!
I don't know the FAF ecosystem very well. But why can't a central server be used for games? Why is the concept of "Coturn Servers" used with connections to each player instead of a single game server?
I am experienced Java Developer with 6+ years of Java-based enterprise application. I'm interested to know what problems prevent us from moving to a client-server architecture.

Please take a look at the diagram below and indicate the problems with this implementation:

The diagram is in better quality: https://drive.google.com/file/d/17jnYO3a58oMZonGRF6Q7PKkCtLwqhsxq/view?usp=drive_link