ive been using kodi (xbmc was better moniker) since google killed sagetv. i recall attempting plex, but it seemed to lack some open/extensibility (its been awhile).
i have a side project i want to make as a modular plugin generating a cable layout with original air orders and networks/channels... kodi seems most optimal, but ill admit its been a long while since i looked at plex.
Every time I tried Kodi, I could make it work, but it was slower, uglier and less reliable than alternatives.
But I don't do Plex, I use Jellyfin. Plex feels like one of these games where you pay full price and it keeps bothering you to pay even more for extra stuff.
I use Plex and have the 'lifetime' licence.
There have been bugs that don't get fixed for years, while a bunch of new features I dont use keep getting released.
These are incredibly infuriating; downloads, server not connecting until app reset, library browsing glitches that only get worse each year...
I have not switched to Jellyfin yet due to my specific setup, but it will happen, or I'll go mad, whichever comes first.
I use Kodi with the Titan Bingie Mod v2 installed as the front end skin. It looks and controls exactly like Netflix, which isn't a great streaming service anymore, but their UI is probably the best and most familiar. Only trouble I have is that I can't connect to my server via VPN, only a rawdog connection, but it's my home network so I'm not super worried.