Discord has easier user acquisition. Also anyone can set up a discord "server" and even the smallest fiefdom of power is like crack to people, so of course now there's a discord server for everything.
I keep saying that this is something discord pushes subconsciously and it makes a lot more places unliveable.
On IRC chans feel more open and sociable than discord. On discord most servers come up with a lot more rules, a lot more steps (get a role) and people were often very tense. I had very sad and angry bouts on irc but it was rarer and about a topic disagreement / douche behaviour and not about bowing to a small group view on how to talk or laugh. It really gave a sect feeling. Then there are the slughtly5 political discord servers where you get a background check before the right to see rooms. Really odd (unless you're deep into anthropology)
And if you just want an irc server for a couple friends you can just ignore ChanServ/NickServ.. it's not really needed (hell.. ircnet is still going strong and has no services at all!)