Your freedom is in the (theoretical) ability run your own instance and communities on it if you disagree with or have been banned from other instances. And your instance can federate with whomever will allow it.
Communities also want freedom -- to be organized and run the way they want to be, and to be free from being hijacked or shit on uncontrollably by randos, bad actors, or even (defined by themselves) undesirables.
It's not perfect. But you sometimes have to consider a bigger picture than just your personal freedom, to make things a free as practically possible.
You seem to have descibed your port forwards backwards It is the router forwarding the ports to the gateway pi (and potentially other devices), not gateway pi and other devices forwarding to the router. The forwards to servers are incoming from the internet.
(Theoretically you could have your pi physically between the router and the internet (modem) acting as a sort of pre-router, but this would be unusual. Perhaps you could describe your physical setup more clearly. What is physically/wirelessly connected to what, to the internet.)