Yep, VPN will allow you to be on the same local network, and they’re only pay walling remote play.

She needs to update her app probably, it works fine for my wife on my server

Plex has pay walled FREE servers streaming to FREE clients only.

If you have a plex watch pass (for client) you’re good and can stream from any server. If you have a plex pass (for server) any one can stream from your server. But you have to have one or the other.

Same with me, 12 years, about $70, and it still works just as well as ever. I turn off any new features I don’t want, my friends and family can still stream from me for free since I have plex pass already, and it’s easy to share without having to pass around my IP address.

Probably because it works well, and has working clients on everything at this point. For some, a one-time fee was worth it when it was cheaper.

Sharing is also easier, as your friends just sign up to a plex account and you share your library with them. No need to send them an ip address and port, or fqdn that you have to maintain if your isp changes your ip address. It has its benefits, tbh, and the core sharing features still work for streaming. All the extra crap you can just turn off.

That why I think its still popular.