That is not at all true if you're anywhere near an urban center.
Even many urban centers in the US are car-centric, especially some of the more affordable ones. Chicago is probably the only affordable place with decent enough transit to go car-free. NY, Boston, and Seattle have pretty good transit, but the total COL expenses in those places still makes them out of reach for poor people. Anywhere else, and not having car will severely impact your job opportunities and probably your cost of living too (good luck saving money by buying from bulk discount stores when you can't carry most of it back).
Name me an 'urban center' with adequate transit where you can live on $1400/mo? Anywhere within 30 miles of Seattle, that's rent.
Single bedroom rent in the Boston area can be as low as $1200/mo. Two bedroom is around $2k. Split the rent with one other person (yes, even in the single bedroom apartment) and the rest to cover food + transportation + bills.
Food, basic cell phone plan (necessity in 2018), health insurance, electric, trash, water. That's either having absolutely $0 left over, or not livable on the given $1400/mo wage.
Don't forget gas and car insurance.
Chicago is definitely possible on $1400/mo. Speaking from personal experience.
That's true for a few, specific urban centers in the US - NYC, DC, SF, Seattle, etc. - but there are plenty of urban areas in the US with really poor public transit systems.
I live in NYC and the deeper you get into the boroughs, the more a car is necessary/helpful, especially with how unreliable the MTA is these days. Also most parts of NYC with good transit, shorter commutes are also probably more expensive rent-wise.
There's news articles about how the worst low income areas of NYC don't have good transport options.
Won't you spend the difference on extra rent, though?
> if you're anywhere near an urban center.
This isn't true even in most urban centers.
Have you been to DFW?
People do car-sharing in the US? I've seen many countries where cars only drive their driver on the way to work.