Not a single student preferred mastodon from discord. Anyone has a link to an introductory article which could show why it's better to use mastodon? I know mastodon is more like twitter replacement, but still...
This is Mur 
@szopen
1) Discord is very different from Mastodon as it is focused on real time chatting which also includes VoIP and video chatting. Beside it is a mainstay for communicating with each other during the play of multiplayer videogames. This is also why young generation is very much into discord.
2) Mastodon/Fediverse is highly populated by nerds, developers as well as people who hate big tech which basically means that a lot of people here have a relating niche or ideology. It's not a place everyone will like, also being open-source and federated isn't much of a cool stuff to everyone.
@szopen
Though as a professor you can always make mastodon compulsory