Another commenter mentioned that they have matrix, discord, IRC, and discourse, however everything but discord is dead. So, due to the network effect of just including discord, it reduces participation on other channels.
Communities that are “discord only” however exclude people like those in this comment section.
I refuse to use discord for all the reasons people mentioned. Personally, matrix + lemmy/kbin/mbin = best. Other opensource direct communication solutions are acceptable too, like Zulip or RocketChat, but only if bridged with matrix. Then I just need one account. For async, discourse is alright, but not my favorite.