An original sin of Free Software which carried through to Open Source and infects HN via its many Open Source believers is a reluctance to take project management seriously. OP shows that Jellyfin’s dictat... er, maintainer is not effectively managing the project. Open Source has no adequate answers (“fork” is not adequate).
The problem is that despite using the same DVCS for source code management, other projects insist on a hub-and-spokes development model, which does not scale.
Projects would be a lot more productive (and a lot more resilient) if they also followed a model where "The <x> maintainer hasn't accepted my pull request" just wasn't a big deal.
1. Free Software / Open Source are Good and True by assertion. There is no God but source code, and Stallman is its prophet. 2. Questions whose answers tend to contradict point 1., such as “Gee, the world runs on Python — as wonderful as job as Guido and his inner circle have done, is it time to ask what an ideal management structure for a technology worth (tens? hundreds? of) billions of dollars might be?” are not welcome — are largely not asked.
(There could be a long discussion here about expectations placed on unpaid maintainers, and what the real purpose of Open Source / Free Software is beyond merely being zero cost at the point of use, but those tend to just go round forever. There's even a paid alternative to Jellyfin: Plex.)