I stopped watching the Roku channel quite some time back because I could not tolerate the loud commercials. I don't know if they're still broadcasting commercials at those screaming loud volumes, but if so, it may not be for long.
https://thestreamable.com/news/lawmakers-introduce-bill-to-limit-volume-of-streaming-commercials
That’s exactly what I do, mute the TV during commercials. If the sponsors want us to watch their commercials, they need to get Roku to keep the ad volumes the same as the programming