When I was attempting to play a program already covered under a channel subscription, Roku wanted me to subscribe to another channel to access the same program. I was unable to access under my subscription. This not an isolated case and reeks of unscrupulous "bait & switch" type tactics! I would like to think program error. Perhaps others have observed similar issues.
This is what I recently experienced.
If you use the Roku search to find something, it will prioritize services that have tie-ins with Roku.
You can use JustWatch and Reelgood (websites and/or apps) to search, keep track of things across services, etc...