But, more broadly, the problem is that they can do it for their own apps, but for all the third party ones, it's down to app developers whether they want to put in effort to support keyboard & mouse/trackpad properly. And it's a chicken and egg thing there - relatively few users use it currently, so there's little motivation to add support, which deters more potential users.
Funnily enough Windows is the closest to get this right with 2-in-1 tablet/laptops. 2 problems with this: 1- Windows, 2- sub-par HW.