I could see it happening, though I suspect that it'd probably require getting the pilot out of the equation to bring costs down. Like, use short-range hops using electric aircraft to yank people out of London to transport areas outside.

You put something like this in London.

An animation on Joby's website shows one such journey, from a heliport in downtown Manhattan to John F. Kennedy International Airport, completed in seven minutes (as opposed to 49 minutes by car).

Joby founder and CEO JoeBen Bevirt told the Washington Post in 2021 the company hopes to begin services at an average price of around $3 per mile — comparable to that of an taxi or Uber — and eventually move that down to below $1 per mile.

"Our goal is to actually be competitive with the cost of ground transportation, but to deliver you to your destination ... five times faster and with a dramatically better experience," Bevirt told Bloomberg TV on Wednesday.

Convert it to a UAV, so now you don't need the pilot. And then it just blips back and forth to the outskirts, linking to parking lots/airports/train stations/whatever.

It's not as energy-efficient as a ground vehicle, but electricity is also cheaper than fuel, and we've found automating aerial vehicles to be a lot easier than ground vehicles.

If you can stack things vertically and use a computer to control stuff, you can get a lot of density; your constraint on throughput is probably your landing space in the city.