One of the main things that made me make the switch to Jellyfin last year was the constant pushing of the ad-supported and other internet based streaming content. I was getting tired of pinning my local media libraries only to have them buried at the bottom of the list again under all the other streaming content after the client apps would update on my family's Rokus. Hardware transcoding is also a nice bonus since I only used Plex's free tier.
They raised the price a year ago too. I suspect OP is like me and paid for a year right before last year's increase.