Buy an AppleTV.
Google devices are out because they are developed by a advertising company.
The Roku CEO outright said they sell Roku devices below costs to advertise to you.
Apple is already sending spam notifications for stupid bullshit like that F1 movie.
My TCL/Roku TV recently started showing popups during streams with services like YouTubeTV and PlutoTV, that basically say, "Click here to watch this same program on the Roku Network". I poked around the settings on the TV, and sure enough, there were some new "smart" settings added and enabled by default. I disabled the settings, and the popups stopped. But it's only a matter of time before something else appears.