There's a popular-ish open source game I remember playing a few years ago, Warsow, and when I checked on it now, it's been forked and while the fork is genuinely better and funner to play in so many ways, it expects to be launched through Steam. I wanted to tinker with maps and stuff and started researching, and while I did find what I was looking for somewhat in older Warsow-related threads, when I went to the official warfork-qfusion github repo looking for specific documentation for the new fork, I was greeted with a link to their Discord "if you have any questions".
Yet this game brands itself FOSS, and it is technically released under a FOSS license and their github shows that they are actively developing it in cooperation with a community - just not a community you can be in without accepting certain walled gardens. It honestly sucks to see. I wanna access threads discussing this software, but I won't be able to unless I go through an ID verification process and trust a silicon valley company to both secure my data and not use it in some nefarious way. And to even run the game, I had to accept Steam, which I honestly didn't have to do in order to run Warsow back in the day, and I enjoyed that - what was wrong with just shipping a binary and letting people launch it how they like, with optional integrations? What's wrong with having an open forum for tech questions? Why wall the garden that you're making supposedly open products in?
In short, what do you call projects like this - the increasingly common projects that, while technically FOSS, put all their documentation and discussion on discord, and seem to expect their users to swallow unsavory default options or even use proprietary middle-ware or launchers? Proprietary FOSS?
People like the immediacy of live chat, which forums can't really replicate, and Discord provides voice chat. For certain things, I can't deny Discord is a more convenient format, so I see how it attracted people. Another big thing is it's totally free. Your tiny pet project with no funding or your tiny group of friends can have their own personal community at no cost. It's not terribly surprising to me that it gained so much ground. If someone was willing to hand out free, full featured communities on a different platform, they might be able to rival Discord, but Discord only offered it under promise of later enshittification, so I don't really expect anyone to step up like that.