There's a worrying number of instances where people managing a foss project using taking their GitHub issue tracker, discussion boards, or some other public forum / discussion board and deciding to lock it and direct users to a discord guild because it's "easier". Or new communities that start up exclusively on discord but would be better served by alternatives.
Except it's not easier, there was an instance where a community had been using a discord channel as a file sharing platform for mods. An administrator was doing some housekeeping of the channels and accidentally deleted the entire chat history (which is easier to do than it sounds), and so irrevocably deleted all of the uploaded files, some of which were never recovered.
I'm pretty sure Digg, Facebook, Twitter, Tumblr, et. al. killed off classic forums. Discord and Slack and killed off IRC [though by and large, most will tell you that rumors of its demise is greatly exaggerated].
