Jellyfin isn’t meant to be used for remote streaming, isn’t compatible with most devices people use to stream media too, and is a nightmare to share your library with friends and family.
Plex solved all of these problems like a decade ago, whereas the JellyFin devs don’t even acknowledge them as problems, more just “out of scope”.
They won’t kill existing lifetime licenses, that would cause immeasurable damage. They’ll just stop selling new ones.