I've only ever used jellyfin and I've loved the experience. For me it was easy to set up and put media on, simple to put on TV, has been utterly reliable and stress free to manage.
The only issues I've had has been tailscale sometimes being wonky or I personally did something dozy on the server machine that I had to fix.
That said, I get why people stick with Plex. Not everyone wants to or are capable of setting things up. For those that have been saying it's really easy, you don't know the other person or their confidence/skill sets, don't just assume, it makes you sound like a Linux bro.