Anecdotally, for me, I can't watch regular movies through my Comcast box. I have to log into the app on my phone and cast it to the TV. Plus, trying to watch TV shows through the app is a shit show. Any other streaming service, I can search for a show on Comcast, and when I select it, it signs in to the app and plays it. HBO Max, I have to sign in, find the show, and make it play.
There's also this:
Comcast is your problem.