Sure, strictly speaking, of course there were accounts as in "database records". However, users gave no details about themselves, and haven't signed up for anything. No long-term credentials, just a rendezvous point.
You used to just open two Firefoxes, start sync setup on the one, copy (or scan) a code to another - boom, done, they're talking to each other.
https://www.youtube.com/watch?v=3G3_Xa1GBTs
https://github.com/magic-wormhole/magic-wormhole