I use it for my family, everyone has their own account which can have their own parental controls. The 'watch together' function has been pretty useful for watching the same thing simultaneously over multiple households & Zoom.

You don't need a plex-pass subscription but it does provide a few new features for keeping track of what everyone's watching.

Kodi is not as end-user friendly for non hobbyists. I’d argue Plex fits the use case for most and Kodi is more capable tinkering. But even then I prefer the plex interface much more and use that myself.

I run a Plex server, but only for family members who live out of State. I have to pay for Plex Pass because I share out my HD Homerun Prime (3 tuners) so my sister in Ireland can watch NFL games. I personally dont use Plex and prefer Kodi and straight up smb file shares. In the past, I would find a plugin for Plex that shared out the tuners, but a server upgrade would always break the plugin. Did this a few times, then gave up and now I have to pay for Plex (Jellyfin needs to mature a bit).

If you have a dedicated PC for this, good luck at getting it to place nice with a VPN like Private Internet Access. After I upgraded to a Ryzen7, I found my family couldn't connect so long as the VPN was enabled. So basically I bought a cheap Celeron PC stick and do all my VPN stuff on that. On the old PC, CPU usage would hit 85-90% (2007 AMD quadcore athlon) with the Ryzen7 its 30% with both of them watching live TV, this allows the PC to also work as a normal file server to several TVs in my house. Almost any old PC will work as a server, but if your sharing out a digital tuner, it needs to be fast.

Generally, I would recommend Kodi over Plex as it has all the features of Plex but it is completely free. Kodi is also more customizable and has tons of addons.