I'm surprised to not see more comments like this. I think chat clients are a product which is used so frequently that after adapting, users become blind to defficiencies. I consider myself pretty technically literate and have used probably a dozen chat clients over years. Discord is the only one where I couldn't understand how to do the basics straight after installing it. I don't use it much, and when I come back to it there's always an element of guesswork. (fwiw I'm not a fan of Slack's UX either)