I can't help but wonder the same thing. The only ROKU app that I have problems with is Fox News App. Same problems as everyone else has described which means the problem can't be all of our devices, providers, etc.
My solution is I just bought Amazon's Fire Stick and will be unplugging my ROKU on Monday. I have numerous ROKU devices and really tried hard with every "troubleshooting" tip. All devices and apps are up-to-date.
I can stream Amazon Prime, CBS, Paramount, Disney+, Britbox, ABC, etc without any issues.
We have all been complaining about this specific app and ROKU for nearly a year at least. Very sad that it is "still being worked on" without resolution.