Roku is exploring ways to show consumers ads on its TVs even when they are not using its streaming platform: The company has been looking into injecting ads into the video feeds of third-party devices connected to its TVs, according to a recent patent filing.
This way, when an owner of a Roku TV takes a short break from playing a game on their Xbox, or streaming something on an Apple TV device connected to the TV set, Roku would use that break to show ads. Roku engineers have even explored ways to figure out what the consumer is doing with their TV-connected device in order to display relevant advertising.
You can even install Kodi on a chinese Android TV box that you can get for $20 from AliExpress. (Just download the APK for the latest Kodi from their site as the Google Play version is pretty old).
You do need to sail the high seas to put together a collection or get some kind of piraty Add-On with On-Demand functionality and getting a VPN is recommended for both.
I think you can install all the normal streaming apps on Kodi as well. It definitely takes more know-how than using something like a Roku or smart TV, but FOSS be like that sometimes.