Why it specifically? Root is yet another closed source service, so if they also start to cause problems, moving away from it it'll be an hassle.
I'd rather consider something like Zulip. https://github.com/zulip/zulip
At least, if there's any issue you can just host it elsewhere.
(Other alternatives which are also open source are Matrix and RocketChat... Matrix has lots of attention, but the UX still has issues)
My2c: I don't actively use Discord, so it should be someone who knows the importance of all features who should decide.