Github I can understand to some extent, it's a convenient temporary staying place until they can afford, community-wise, to move to something truly open, but Discord? In this day and age?
Discord IS the platform of this day and age, what the hell are you talking about? You might not like Discord for whatever reasons, but trying to make it sound outdated or legacy is very weird sounding.
There was a hype for discord about 5 years ago for EVERYTHING - discord servers were made for every little thing and there was little to no objection about it.
But in recent times, I have seen many people complain about the lack of searchability, discussion-thread management, and other stuff in Discord and moving away to forums, especially for software projects. There is definitely a lot more disgruntlement with Discord today, so their statement makes sense.
It is a non-starter.
Not public. Got to register an account and accept Discord ToS first.
What’s your recommended alternative?
(However, GitHub is accessible by git in case you only want to download the repository, regardless of what else they do; however, having multiple mirrors on other services as well can be helpful)
So, IRC, Matrix (these can even be interconnected) for synchronous, mailing lists or forums for asynchronous.
And of course issue tracker, where some topical communication can happen as well, but that could completely be covered by mailing lists.
There's no reason to ever have anything non-open in your FOSS project's infrastructure.
Because that is a project in itself and as much as I despise discord, I understand why they just went with it.
