Let’s say I decide I’ve had enough with this whole Federation business and that humanity would be better represented by a Starfleet that follows my particular ideology. Assuming I could get enough people for crew and support, why can’t I start my own Starfleet?
I could replicate ship parts until I have a couple vessels. Go to new worlds and present myself as the official first contact of humanity. I could fly to Vulcan or Bajor and tell them no actually my organization represents humanity.
What’s going to stop me?
No elements can be replicated. Replicators rearrange existing atoms.
I’m reasonably sure this is not entirely correct. My understanding is that a replicator works similar to a transporter, in that it turns pure energy into matter according to a known pattern.