Unfortunately I had a pretty bad experience with jellyfin when trying to switch from plex. Plex works for me in almost all scenarios, mobile, desktop, chromecast, what have you. And I can play multiple feeds simultaneously from my cheap Nuc server. With Jellyfin I had trouble to get video even playing without stuttering/buffering on my phone when on the same network, let alone on mobile internet. I'll probably give it another go in a few months to see how they evolved.
Right, I can understand this. In any case, it's very hard to define if something is more performant than something else due to the vast number of metrics available to estimate the performance. Are we talking DOM manipulation, time to interactivity, SSR, number of parallel requests? With today's full-stack frameworks, it's even harder to put a number on these things, let alone make a ranking.