You can walk more instead of driving. You can ride a bike or scooter instead of driving.

Unfortunately this is not the case in many US cities. I saw a post on Reddit a few weeks ago about how small European refrigerators are and someone asked how often they go grocery shopping. Someone said "Every day. The grocery store is only a half kilometer walk down the street". In many US cities there's nothing within a half kilometer, not even the next street intersection. I think many parts of the world massively underestimate how large and spread out the United States is. The single state of Texas covers half of Europe. Texas and California combined cover almost the entire continent. In most major cities with conservative governments, there's inadequate public transportation too. So you can't walk, biking takes forever & it's 110 degrees outside, and there's little to no public transportation.

I'm fortunate that I live in a city with both good public transportation, and good bike lanes. When I reported to the office every day I'd take the bus half the way there, and then bike the other half. But I had coworkers that commuted 50 miles by car each way, each day. There's no public transportation or bicycle that can handle that sort of commute, except for possibly the subway in NYC. Yes, people can choose smaller cars if commuting is their only need, but like you pointed out, some families are large and need larger vehicles.

The large family situation is honestly another area where we can improve for the future of our planet and species, but people treat you like the devil if you talk about it. The global population has more than doubled since I was born. There are 8 billion people on the planet and that number continues to grow exponentially. Our planet cannot continue to sustain the human population and its insatiable desires if we do not reduce our numbers. There's no need for huge families anymore in most parts of the world. Infant mortality is at an all time low, we have modern medicine, and we have security nets for catastrophe. Nobody needs 10 kids anymore, but for some reason it's still considered faux pas to say that.