You would need to find an instance of peertube that is following all other instances. There are several peertubes that try to follow as many other instances as

You would need to find an instance of peertube that is following all other instances. There are several peertubes that try to follow as many other instances as possible, but there will always be private or unadvertised instances. If nobody knows a particular instance exists, then nobody can follow it and its content won't be discoverable.