Aha, a tangible argument. You don't see the possibility of social bifurcation from 30% of the population not being allowed to drive?
Most tradie jobs require a car. It's very hard to be an electrician, plumber, chippie etc. that services homes as if you don't have a car. It might be possible to do commercial work in those fields without a car but every apprentice I've ever known has needed one to carry around the huge pile of tools they're expected to bring on site themselves.
There are also a lot of entry level unskilled jobs that require a drivers licence (assuming you consider a drivers licence "unskilled", which it sort of is but wouldn't be of 30% of current drivers had their licence revoked overnight), like delivering pizza or doing private courier work.
So yeah, changing driving laws to make it a requirement that drivers be consistently safe, courteous and predictable and refusing to give licences to people who can't meet that criteria would definitely be a social bifurcation because it would all but eliminate whole categories of otherwise relatively accessible industrial for the people that cannot get the licence, and in so doing widen the already increasingly wide (lower/middle)/high income divides that most western nations are seeing.
However, that was not my point. My point was that the argument "we shouldn't let people do this because it has costs to society" doesn't really go anywhere as an argument. That's true for pretty much everything we do in society, it's a nothing argument.