Some very-well-requested features/clients have gotten no traction at all, with no one coming in willing to start/help developing them. We've had to abandon some (like Chromecast for a while, though it's getting new life in the last few weeks) because of this.
We're aware that probably the biggest complaints about Jellyfin are about the lack of client support, and the rough edges/lack of polish. We do hear you. We do want this to improve this just as much as you do.
But we need people to help us do so. We need more volunteers who can help make the code better, write new code, document, and generally improve things. We need your help to push past what I call the Development Bystander Problem, get some new blood into the project, and especially, help to make it better!
https://jellyfin.org/posts/a-call-for-developers/
It's noble to want to be a 100% volunteer force but it's frustrating that they know they have issues and a big pot of money but won't solve them.Even without paying for development, money could be spent to improve the developer experience and attract new devs.
They have acknowledged client development is an issue in the OP and the link above. Could they not support client devs with hardware, licences, costs, etc...