That sounds pretty revolutionary to me already? Why don't you think so?
There's lots of existing plans to improve those other things too, pedestrian only zones, car-free superblocks, e-cargo bikes replacing some commercial vehicles, bike shares, subways and metro systems, bus rapid transit corridors, seperated bike-lanes, mixed-usage districts so that people have everything they need within a walkable radius.
Plan for cars and you get cars, plan for people and you get people.
Even if I accept your premise that cities are descending into "Escape from New York" territory, how does allowing ICE cars to spew pollution do anything but make that worse?
Do you have a source for that? Here in NYC things seem as popular as ever, with record-breaking rents due to high demand. Is it different elsewhere?
Regardless, even if it's true that some cities are struggling, that only makes it more important for them to focus on improving quality of life: a rise in WFH means people have more options, and a city that doesn't want to depopulate has to be an attractive place to live independent of economic opportunity.
Removing private cars from cities won't revolutionise them, when the roads are still going to be full of commercial vehicles, buses, and taxis. Yeah, it'll make it somewhat safer for cyclists and reduce air pollution and noise a little - but not enough to turn a declining urban dystopia into a desirable place to live.
Unless of course, you're very wealthy and can live in a luxury apartment with good security and plenty of distance from the 'rough areas'.