Same. Several years ago I was a happy Plex user, but our Internet got knocked offline and we wanted to watch some local content, no dice. I canceled my Plex Pass sub as soon as I had Internet again. I use Emby now which offers pretty much the same experience without the need for a permanent Internet connection. Their subscription offers a few bonus features but it's not required for LAN streaming.
Not that I'm trying to convince you to come back, but Plex does work without internet access. The Roku app allows you to set up a fallback ip when it happens as well.
I don't love the cloud login either, but I do still use it. Just wanted to point out that the server and (some?) clients work without it.