There's just no reason to waste the energy, the coordination effort or take on the risk.

I do agree though that they make a lot more sense than drones, for several reasons: (a) power consumption / mileage per charge (b) carrying capacity (c) safety in populated areas (d) privacy when flying by buildings (e) lack of suitable landing areas in urban centers (f) noise in residential areas.

Source: I am the co-founder of one and aware of internals of several others

Putting robots directly where people are creates way more unknowns than having them operate outside of the normal human space.

Or, more optimally, you would configure delivery windows and tell it when someone will be available and they schedule one or two delivery times in that window.

Legality: how high above your property do you own? Would a drone flying at 50 feet be trespassing? 100? 200?

Loss: how do you recover a crashed drone? Or one intentionally downed?

Range: how much power can you pack onboard without compromising payload capacity?

Payload capacity: how much can you reasonably lift?

Cost: dollar for dollar, is it more cost effective than trucks (even robotic ones)?

And so on.

Drones are loud. Incredibly loud.

Also it would seem it’s not an energy efficient way to deliver goods to people, but who knows. Paradoxically it would make sense for high value/low mass items like medicines (or narcotics too), but that would make them a more enticing target.

Delivering tacos or sushi on the other hand... maybe years hence.

Piloting the drones isn't the problem- the problem is logistics, noise, regulation, costs, etc.