I use both, for different things, and I far prefer Slack.
What do you prefer? I can think of a single thing I like more on Slack, maybe two if I'm splitting hairs (it's a dev only thing) but I moved my entire company's internal chats to Discord (where our external chat already was) because I strongly felt the opposite!
They already have more users than Slack, so I think their response to that right now might be shrug
The fact that you can't easily reply to a message in discord kind of tells me the opposite.