Agree to disagree about economies of scale, but FYI busses are ~$500k and seat ~40, meaning ~$12.5k/person. There are a dozen manufacturers of electric 2 seaters today that can build for a quarter of the cost per person, or half if you assume 1 person occupancy. Yes the area per person is larger (tho not by much), but you can make up for that with increased throughput by way of point-to-point operation without stops, faster speeds, and more.

Focusing on rollout, municipal light rail almost never gets deployed in US-style cities due to huge capex, not opex. Smaller vehicles allow incremental roll-out and can use preexisting road infrastructure. Ergo, that's the form of public transit you're most likely to see grow over the next decades.

Drone here doesn't imply flying, it's about scaling down wheeled vehicles and the coexistence of a wider variety of vehicle sizes on roads that is unlocked by the automated movement of mass. Delivery to higher up floors can be done through small in-building elevators. If you think that's unrealistic, consider that it was once extremely popular to use pneumatic tubes to send mail in buildings. Built infrastructure changes based on what is possible, and mass needs to move.