I’m pretty sure he means other people at his uni use instagram and the likes. Signal/Simplex/etc. is great, but at the end of the day, sometimes you don’t have a choice and must use what everybody else is using.

It’s not because everybody should be using these apps that they will. If you have a group project and people want to communicate on messenger, that’s what you are gonna do. Not doing so would make you insufferable and no one would want to work with someone that imposes his choices on the group.