if your userbase is not just IT workers and FOSS enthusiasts (...) Plex is the place to go.

What does this even mean? My 6 year old niece uses jellyfin, it's actually simpler than netflix. I may be biased because I'm not into frills but I think the UI looks great. I've admittedly had a few non-critical bugs with the UI (web, flatpak, android, roku) but most all of them have been worked out now. Plex is more polished and has a much larger ecosystem like you said, but the rest of this comment is not the most reasonable.