Because mobile phone wireless projection screen is also required to support performance, cheaper box or cheaper TV even if the projection screen will be stuck, pro test. The only feature that doesn't require performance support is a wired projection screen, but not many phones do. And a hard injury is: 16:9 mobile phone is too few, non-16:9 mobile phone direct projection TV will have black edge. So you need a box that works anyway. In the future, you can buy a non-smart TV from LG or SONY and still use the box.