AppleTV would be my recommendation for people that want a clean interface with no ads and they don't want to or can't modify an android TV box to a custom launcher. It's just about a perfect experience right out of the box. It's a shame about the shitty remote though.
For people willing to get their hands dirty, androidtv having SmartTubeNext is a killer tool for YouTube and for me gives it the edge.
Not for a while, at least not on their flagships.