I used to feel the same way about Plex til they started flooding my less savvy family with ads for their own content and useless features unrelated to what they want to do. Really not impressed by that one. I realized how bad it was when I got a call about a broken movie I didn't even have.

Plex still seems slicker than Jellyfin in some ways but after that experience I'd certainly consider a switch. Offline is the only reason I still use plex, but their offline setup is pretty buggy too.