I find the Discovery channels programming to be okay. That said, their commercials are nearly 100% of the time promoting Discovery + , which must be hurting, They keep running the same moronic commercials, many times, twice in a row, and occasionally three times in a 6 commercial block. What, do they think the watcher will have an epiphany and all of a sudden want to subscribe to it? This is annoying as h*ll and will keep me away from their programs. How about replacing them with time occupying zen moments like some clever channels do?
What Discovery does with their commercials is up to them.
Discovery Contact Us page: https://corporate.discovery.com/contact-us/
My posted complaint is not aimed at Roku, per se, rather the source of the problem which is Discovery.
I wouldn't assume that anyone from Discovery or any other content provider, monitors this forum in any serious way, so I would also use the link that @makaiguy provided.