The discussion seems very muddled and opinionated ITT because I'm not even sure if you're talking about a Discord Server or a forum/communication platform on a dedicated server. You might be able to slap together a Discord server faster, but the organizational power and not putting that extra work on users for Discord participation makes forum's superior. Part of the project development is sysadmin. If it's not, why take it FOSS at all? Discord is designed to take up your time, those pretty bots and "perks" keep you viewing. What could've been a well thought out message on a board with a reply now becomes 20+ texts which you're stuck communicating on. Rinse and repeat every day, on a forum you simply link the previous conversation and you're done.

I think it's a neutral wash atm, Discord may be packaged better to be mainstream but it's bloat all around with lots of negatives. Anyone saying Discord is better is just preference at this point, lots of counterintuitive comments like we need "real-time" communication but also anything else takes up project development, like Discord is some kind of time saver.