Yes, because we often have to be in different places at the same time, which surely is obvious.
For example, I used to commute into work on the 6am train and not get home until 7:30pm. If we only had one car, dh wouldn’t have been able to get dc to school (2 hour walk) and nursery (another 2 hour walk in a different direction) or to work (20 minute drive so he wouldn’t get there in time to turn around and come home again to do the school run 😂). No public transport where we live. Okay, well, there is some, but it’s like Tuesday and Thursday 10am returning at 4pm from the nearest town (which is not even the direction we need to go).
Or once or twice a week, Dh is 2 hours away for work. On those days, I need to get dc to two different schools and then dropped off to activities at 4:30 and 5:30 and collected again at 7pm and 9pm. Again no public transport. We don’t have taxis out here either really, but if we did, would easily cost £100 a day. I also have cancer and need to make frequent trips to hospital, which is an hour away. If I couldn’t drive myself in my own car, it would mean at least 4 hours a day of driving for Dh to drop me off and pick me up around the school run (never mind him actually going to work!).
We simply live too rurally and are too busy for one car. The only couple I know who share a car live in a London suburb and worked for the same company, so commuted together, and were just unusually attached to each other such that they went everywhere in tandem. Would drive me nuts following dh around every day.