As a long-time IRC user who never had problems with various IRC clients, I find Discord's interface quite counter-intuitive.
First example that comes to my head: I click on a channel that I haven't visited for some time, the view focuses on old messages (from the last time I visited it) rather than on the newest ones (which is typically what I want). And going to the newest ones isn't even trivial, I don't know a way other than scrolling down all the way, which may be quite annoying if the channel is very active and there is a lot of material to scroll past.
First example that comes to my head: I click on a channel that I haven't visited for some time, the view focuses on old messages (from the last time I visited it) rather than on the newest ones (which is typically what I want). And going to the newest ones isn't even trivial, I don't know a way other than scrolling down all the way, which may be quite annoying if the channel is very active and there is a lot of material to scroll past.