"But, but, you can rent a car with a car seat!"
That response ignores the fact that there are 4 different major categories of car seats, most kids need a specific one at different times of their lives, and if you have multiple kids you need the specific combination of seats. And of course, car seat installation is hard and takes time, even with LATCH, and I wouldn't trust a random Uber driver just handed a seat to install it properly.
It happens at home as well. I don't need to bring a bag for evening activities into work because I can just leave it in my car. And I don't need to bring my computer bag to an evening activity for the same reason.
Sure, all this stuff can be worked around when it has to be but there a lot of advantages to having a mobile vehicle you don't have to empty every time you arrive at a destination.
Given proper public transportation, I did. Not owning a car is not only a lot cheaper, it's also quite liberating: - I don't fear I'll wreck it, or worse, I'll badly injure someone in a car accident - I don't have to drive and be angry about other people on the road, like a lot of drivers - I'm not owned by my car, that requires maintenance and cost beyond just running it. - Not fighting for parking spots!