But even if car people lived somewhere with the best public transport in the world, they would drive.
It’s not about technology or even reality. This conversation is a lot like trying to tell private health insurance users about single payer systems. Or private school users about federalized education. Or telling people with 4 children or 0 children how to live in a world where a thing like the sedan is designed for people with 2 children.
It is telling rich people you know better and also they are wrong, which is not an emotion you’re permitted to send.
Busses accelerate, decelerate, and turn differently than cars, so even if in terms of steady-state flow the two-riders = break-even argument is correct, it's not in city traffic.
Moreover, I'd like to see your work on operating and capital costs, especially accounting for road wear for which the usual approximate rule of thumb is that it varies with the fourth power of vehicle weight.
And remember, the City busses are running only every 15 minutes. So whatever effect they have on localized traffic, it's very intermittent.
I don't think there's anything fundamental about density. Its about ridership and funding. Even LA could have functional mass transit if it had the will to fund 15-minute busses on a grid all day. A 25 cent tax on gas would do it. If even 2 people average rode each bus, it'd break even on traffic density as well?