The point is this: if you live in a city with bad/no public transport, then a car is necessary for going about everyday life. If you live in a city with good public transport, it's really not.

Given the fact that car infrastructure competes for resources with public transport infrastructure, and is vastly more expensive per person-km, and vastly more dangerous as well, prioritizing efficient use of public resources trumps personal comfort when looking at this. The same can't be said for housing, so the comparison is not relevant. Plus, there are very objective reasons for which privacy is an absolute requirement at home (mostly to do with vulnerability and sexual behaviors), which also don't apply to cars; especially since the kind of privacy you get in your own car is actually quite limited anyway - it would be both illegal and quite unsafe to drive around naked, at least in a bad neighborhood, for example.

Private houses aren't killing tens of thousands a year.