

Yes you can. If you know what you’re doing with networking, the Plex instance will have no idea whether you’re remote or not. You can make every remote user look like they’re internal to your network. Plex would have no way to stop that. They could incorporate more intense DRM, requiring things like same GPS location, but even that could likely be spoofed.
You don’t need a VPN to trick Plex. Exposing the web ui to the world will likely show traffic coming from your router, which is internal. If it doesn’t, you may have to mess with some settings, but a VPN isn’t required to access the web ui.
Jellyfin is also very limiting based on your users devices. There is no Jellyfin app for Samsung TVs (without sideloading) or Playstation. Users there are shit out of luck.
The thing you’re failing to grasp is that Jellyfin is not nearly as simple as you’re making it out to be. They both have trade offs. One or which being every single Jellyfin app is complete trash.
If Jellyfin works better for you fucking go for it, but claiming this is the death of Plex, Jellyfin is way easier, is laughable.