In the military, especially when stationed in any area sprawling out over wide rolling hillscape, and given the bustling nature of work in tactical units, it's almost inevitable that just about every service member will need his or her own car. So being in different units with different offices, DH and I got used to each keeping of us keeping our own car.
But you need not have been a service member assigned to a sprawling middle America duty station to fall into having this "need". In any metropolitan sprawl you'll come across countless households who rely on one or more cars per adult in the household (and sometimes one or more cars per person including the babies!), without giving it much thought.
Sometimes their established lifestyles make it necessary; each have to commute in opposite directions, or shifting jobs or companies every 3-5 years for some reason or other. But many keep up this avenue for needless spending simply due to convention and social norms.
But in my quest to become more frugal I've read a lot about reducing the number of cars you own or going carless altogether. This suggestion is among many that encourage readers to consider deviating from the norm with the goal of improved financial health (such as a small condo close to work instead of a McMansion out across 30 miles of rolling suburban sprawl, or maximizing your retirement allotment over maximizing other avenues of lifestyle inflation).
Both of our cars were having recurring and expensive issues, so after a few years of carpooling together to the same building, we finally decided to try going down to one car.
So I sold my car and DH traded his in for a slightly bigger automatic sedan for the family. It's been about a year-and-a-half now and things have been working out quite well! There have been maybe a few occasions you could count on one hand for which we needed extra transportation such as a special appointment far away - DH once used a rental car for the day, and then started using Uber. That car rental was over a hundred dollars, but still a small fraction of the combined annual maintenance, insurance, taxes, and gas of keeping the second car. So even with those occasional expenses for transportation, the edge still goes to keeping one car instead of two.
Which ultimately leads to automatic extra savings in bank, and slightly bigger steps toward financial independence.