Earlier quoted context omitted.
You say this has nothing to do with Chromecast and then describe the #1 use-case for casting, to play movies that sit on your device (phone, laptop) on your TV. Jellyfin, based on their website, looks like just another media server.
The #1 use case for 'casting' with a chromecast in my house is absolutely to stream from online services to my tv or monitor while controlling it from a device that would melt or run down its battery if it tried to act as a go-between for the data, or had to potentially re-encode data from its storage to what the tv can support. That's still the niche that chromecast fills better than anything else at a price point t…
Yeah, I've always been amazed at how unreliable and broken the Chromecast software seems to be (for me, at least). I feel like Google really missed an opportunity here.
If this hadn't been the case, I personally would have purchased more of them and, importantly, recommended them to many people. But, after a couple tries (gen. 1 and gen. 2), I gave up.