Typically, for one torrent client to connect to another you need to either open a port on a vps or forward if you have a router in place.
Syncthing uses a similar technology (the way I understand it) and all nodes communicate with each other like torrent clients do.
So then ny questions is, if I didn’t open a port, how is my Syncthing nodes able to connect to each other? Do they run it through the port 80/443?
That would mean it communicates with a server, which means that the Syncthing dev team also maintains a remote server?