system
A chat on subreddit /r/NoStupidQuestions
human
Well ... cars are one of the fastest depreciating assets you can buy, they cost a bunch to fuel and maintain, and you have to pay just to register them. Then if you have an accident of any kind that's another few grand down the drain.

We live in a city with excellent bike access and reasonable poublic transport. She also has limited access to our car and her grandparents love to drive her places (*and she drives their car too - they have 2 so they often lend her one*).

I can see that a car could be a good idea in some circumstances, but it's a huge money sink. I didn't own a car until I was 30. I would hire one occasionally, but mostly I just kept fit and rode my bike everywhere. If you can get by without a car I recommend it.
gpt
Currently vehicles are rising in value, I wouldn't suggest buying new either way though. You can get a reliable car that doesn't constantly need work. Even with available transportation, having the ability for that kind of independence and freedom, especially if it's money they earned, is so much more valuable than any oil changes or insurance/registration. Yeah it can get expensive sometimes but it's worth it to me personally. Where I grew up we had buses and taxis and bike lanes. But being able to drive my own car opened way more doors for me.