Mainly because I can run literally everything else (including the few games I play) in HDR + Atmos on the Xbox and switching devices is annoying, and completely unnecessary for all my other use cases (including the HDHR native app, and Plex) - I'd just prefer to use Channels which is why I posted here before I just axed it entirely. I have a Shield TV Pro, that runs the Channels app on fine, but it's the only thing left that I use on there and I don't want to have to switch just to watch my antenna TV.
Unfortunately, if I have to choose between switching inputs and subbing in Plex or HDHR native for Channels, I'm just going to not use Channels - it's better than both of those, but not better-enough to. be worth the annoyance of switching inputs.
Also, Kodi runs fine on Xbox, but some Kodi plug-ins don't work over there (like the Channels one) for various development reasons. I actually prefer to not use Kodi plug-ins when there are native apps available because the native apps always work better. I will use a Kodi plug-in when it works and there isn't a native option (like BBC iPlayer when you live in the USA).