Great idea, beautiful thought, but absurd in reality as of 2019-foreseeable future for many of us
Your assumption that everyone in the world lives in a city is inherently flawed. Those of us who live in the suburbs, rural towns, villages, and in countries where the government cannot care less about enabling public transit (places such as the South Island of New Zealand), the idea of mobility as a service is absurd, at least as of 2019.
That said, I mighty like the grandness of your vision and I am all for the the ideal in it. I’d say you need to extend your theory of ‘absurdity of individual car ownership’ to situations where many of us find ourselves trapped. Say, Do I like to drive or even own cars? No. I have no choice but to keep two petrol cars, both of them are expensive, climate-averse, unsustainable. Do I have a choice? Nope. The only ‘trial’ bus service we have in our boondocks to the main city is from a place 15 kilometer away from my rural town. The diesel guzzing jalopy leaves at 7:00am in the morning and returns at 6:00pm. Nothing, no other service, in between. No train, no other means.
Then, the price of the cheapest car, the ugliest of the ugly Nissan Leaf is thirty grands, with barely a couple of charging station in the 100-kilometer stretch; at that price I get a better designed petrol car on a stretch of highway dotted with petrol pumps. Riding my bike on the single lane highway is impractical to commute for work.
Much as I see value in what you write, the reality in some, if not many situations in the world, is tilted totally in favour of individual carbon based personalised transit. Beat that.