Ryze simply doesn't want that.
Computer vision requires powerful phones, and this does not work well if you produce for the mass market. Most users have rather weak phones, and would bitterly complain about the features not working as expected.
Even with a decent phone you have to stick to a few things regarding light, position of he person in the frame, distance. Even clothing and skin color make a difference.
Such features are too fragile for mass market drones. For the mass market features have to be fool-proof and fully reliable. For the same reason they don't do RTH or smarter autopilots.
The $5 price tag has no relation to the actual development cost of this project. The app will never even cover the Apple hardware that I had to purchase for this project. At least I learned a few things