It is being worked on, it's just hard:
https://www.youtube.com/watch?v=pycyMUQwiNs
https://www.youtube.com/watch?v=Sq1QZB5baNw&t=34s
I'm expecting a minimum of 5-10 years to pass between real-time vision AI getting good enough for level-5 autonomous cars and the same stuff fitting into the power envelope available to this kind of domestic robot.