Usenet is distributed across hundreds (thousands maybe?) of servers. It’s centralized in that setting up your own server and getting the same access as joining an existing Usenet server is going to be very difficult (and with Usenet being used for privacy more and more, could be impossible due to admins not trusting a random new person), but in theory one could.
Replying to this before OP asks.
Usenet is distributed across hundreds (thousands maybe?) of servers. It’s centralized in that setting up your own server and getting the same access as joining an existing Usenet server is going to be very difficult (and with Usenet being used for privacy more and more, could be impossible due to admins not trusting a random new person), but in theory one could.