Chromecast with Google TV has half of the screenspace for streaming service ads. In some locations they have other ads too. This can't be removed even with the "Apps only" mode.

I was kind of forced to get a Chromecast, because they actively block independent receiver implementations, and the prevalent Cast button in Android apps is used by other inhabitants.

This should obviously be illegal, and probably is, but megacorps are above the law.

https://www.androidpolice.com/google-tv-ads/

I never see ads on chromecast unless I'm using an application that has ads, e.g. youtube without premium