Plex uses cloud-based authentication, which means Plex Inc. is holding the keys to your library. I switched to JellyFin because I was not comfortable with that arrangement.
What meaningful keys do they hold to my library if everything is sitting on my hard drive waiting to be switched over the moment something better comes along or Plex makes themselves worse?
As far as I'm aware Plex media server still has the option to whitelist subnets for auth bypass. I don't know if there is an option to do purely local authentication, but I don't believe it's accurate that the company is holding the keys to your library.
but it's still on my hard drive. if i can't log in to plex for some reason, i'll install jellyfin. or mount it as a network drive and play the files with VLC. it's not like they're locking away my content behind their authentication, all they're locking away behind that auth is my ability to access my media through plex.
Are they not also injecting ad-supported streaming content into your library by default? Yes, there is an option to disable this, but it is the default and needs to be disabled at the user level (afaik).
This is introducing a distraction to the point and is entirely unrelated to the point being made. Voice this complaint as a top level discussion if you actually want it to be discussed.