Earlier quoted context omitted.
I (also a lifetime Plex Pass user) decided to try it out ~6 months ago, and I've switched over. I haven't had any gaps in functionality yet, though YMMV of course. While it isn't better than Plex (which is still fine for now), it isn't worse either, and I trust the Jellyfin devs a lot more than the Plex devs at this point.
I must be old school. I never got on board with Plex, because my "lifetime" licenses for PlayOn, TVersity and Twonky all ended up completely useless. Yes, those licenses still work, but you can't get the latest versions which provide support for the latest codecs, features, etc. There's a cutoff on the versions that "lifetime" license allows you to upgrade to, and some of those licenses were not that cheap at the tim…
Don't think of any such thing as "lifetime". Just ask: "For the amount they are charging me, how long does it need to last for it to have been worth my money?" With the price I paid, one year would have been enough.