Electric aircraft that take off vertically, fly short distances, and land on a rooftop have passed certification and carried paying passengers in a few cities. The technology works. Whether it becomes transport is a different question.
What has been achieved
Aircraft certified as safe to carry passengers, which is a substantial regulatory milestone. Demonstration routes between airports and city centres. Manufacturing at small volumes.
The constraints
Where to land. A service needs landing sites in the places people want to go, and those sites need power, safety clearances, and neighbours who tolerate the noise. Cities have few such sites and creating them is slow.
Air traffic management. A handful of aircraft can be handled by existing systems. Hundreds cannot, and the systems to coordinate them are being designed rather than deployed.
Battery energy density, which limits range to short hops and means the aircraft spends a meaningful share of its time charging.
And pilots. Each aircraft currently needs one, which sets the cost. Autonomous operation is the plan and it is not close to certification for passengers.
The economics
Currently a premium service for a small number of people on a few routes. The path to affordability runs through automation and scale, both of which depend on obstacles above.
The realistic picture
Niche services in a few cities over the next several years – airport transfers, specific corridors. Not a general urban transport layer, and the timelines suggesting otherwise are marketing.