As far as logs hosting though, this only works for as long as you're willing to host though. It seems unlikely that Discord will disappear overnight -- or if this was a risk, I'd assume they'd be acquired with a large userbase.
I've written IRC and Discord bots and don't think Discord bots aren't much more difficult. One of the best strengths of writing a Discord bot is that if your bot goes down, you can query and fetch lost history fairly easily. This isn't doable in IRC unless you put a bouncer in front of your bot or the server is set up to feed clients with history.