When shopping around for an Android TV box, you may notice that you can buy a full-on television that comes with Android TV software already built into it. These can be handy if you're in the market for a new TV and know you want it to run the Android TV interface, but they're also a much larger commitment than going with an Android TV box.
Android TV boxes are considerably more affordable than the best Android TVs, making them a lot easier on your wallet. If you've already got an excellent non-smart TV, a TV box is a cheap and easy way to rectify that instead of shelling out the big bucks on an Android TV. It's also a great way to get familiar with the operating system if you've never used it before.
Alternatively, if you get an Android TV box and it turns out that it isn't a good fit, it's much easier to return a small box instead of a giant TV. Android TV boxes also tend to have better processors and get more reliable software updates, especially with ones like the Shield TV and Shield TV Pro.