A dedicated forum, open to read without login, and controlled by the project. They have easy access to all their data, decision-making power on features to support, and it's their call whether or not to allow advertising (they don't) or AI training of their data.

Seems like a perfectly good place for it to me.

We definitely need more forums. And with Discourse being a huge improvement over BB and other forum software from the 90s, it's not hard to set up multiple forum accounts and even tie them to some other login if you want.

I understand abandoning reddit in any situation

Reddit isn’t conducive to many types of conversations due to the voting mechanism for posts and comments.

Why would they want to use Reddit?

Because that is where the users are

Sure. 60k members on r/jellyfin. But if you look at actual activity, comments per post, votes, etc., the forum is now on par with r/jellyfin in its hay day. But now we can pin important posts, guides and walkthroughs, sub-forums to group things together. For example, having Themes be in a separate sub-forum is huge for seeing what your options are.

The only thing you can say in favor of reddit is that most people already have a reddit account. Had, in my case. It is convenient in that sense, but reddit is not better than the forum. And reddit stands for everything that Jellyfin is against.

With all the practical and principal considerations summed together, ditching reddit was an easy, and the right, choice.

The forum has 10000 users and averages around 30-40 posts a day ... i would not say thats "no traffic"

How many were on Reddit? More