Because Kodi is just confusing. When I got my first Android TV, I was reading about Plex and Kodi everywhere. So I tried both. I never even figured out how to make Kodi do a similar thing to what I had with Plex.
Granted, Plex sucks nowadays and I’ll be migrating somwhere else, but it definitely isn’t going to be Kodi - it was confusing and ugly.