It was mixed. People got around faster and stuff was cheaper. On the other hand, we got fat and dependent on cars, which is particularly bad for the poor (since cars are inherently expensive), and for kids' independence. That's why you're seeing many metro areas starting to prioritize walking, biking, and transit.
On balance the development of cars was good, obviously, but let's not kid ourselves, the downsides were significant.
I'm not sure if it is an established fact that people got fat because cars came along (before cars there were carriages). I'd rather bet that diet is the culprit.
On balance the development of cars was good, obviously, but let's not kid ourselves, the downsides were significant.