The one mentioned here does have Google TV, basically an old version of Android unfortunately. I agree with you that it'd be better if they were just dumb projectors, and you can easily get a $50 casting device if you want, rather than obsolete a $1000-$2000 projector.

Most projectors don’t and it’s wonderful. So many smart TVs get loaded up with ads because you are essentially a captive audience tied to a very expensive purchase. Throw a Roku or Apple TV on there and you’ll get the same thing with far less premature obsolescence