It’s a messaging service that has a broadcast feature. And for that multicast/broadcast feature you get to have a crappy peer to peer message experience, be limited to small messages, look at ads, surf through unknown algorithm manipulation of what you read, locked in a single system, and be told you might need to pay to either a) prove you’re “real” or b) not see the ads. Sign me up!!
(A blog is also a broadcast messaging service, so I think you’re both right).