Text:
I consent to Plex to: (i) sell certain personal information (hashed emails, advertising identifiers) to third-parties for advertising and marketing purposes; and (ii) store and/or access certain personal information (advertising identifiers, IP address, content being watched) on my device(s) and share that information with Plex’s advertising partners. This data is used to deliver personalised ads and content, ad and content measurement, audience insights and product development. Your consent applies to all devices on which you have Plex installed. You can withdraw your consent at any time in Account Settings or using this page.
Soure: https://www.plex.tv/vendors/ (Might have to clear cache)
Can also read about the changes here: https://www.plex.tv/about/privacy-legal/
Jellyfin exists because Emby was only open source until it wasn't convenient. Some of their own devs pointed out they were violating the license, and their response was... non-ideal.
So Jellyfin was forked with the last fully open-source Emby code.
At least that's my recollection several years down the line.
I decided then that no amount of headache from Jellyfin (and let me say that I was an EARLY jellyfin adopter AND former Plex user) would be enough to get me to use Emby. (Because things like that are important to me, though I realize they aren't important to everyone.)
And reading this thread I'm apparently a super-genius because I have my Jellyfin behind a reverse proxy and serve it to my elderly parents with a simple login and an app they were able to install, and never found it to be a headache. (Which, if I'd read this thread only, I'd conclude was just not possible without voodoo magic)
No headaches along the way, and whereas Plex had already begun the march to enshittification when I left, Jellyfin has done nothing but steadily get better.
Anyhow, longer answer than intended, but I'd go back to Plex before I'd go to Emby, just on principle.