Also using Jellyfin and it’s great.

Regarding the number of different clients, yes they have less than Plex but remember Jellyfin is a free product and is a considerably younger project so more clients will come in time.

I run a Jellyfin add-on with my Kodi setup and it runs great and streams to three of my mother’s LG TVs, one uses a web client as the official client hadn’t been signed off by LG, another uses the official client (LG run multiple versions of their WebOS) and the third runs the official client on fire stick from the Amazon app store.