By "many", I understand you mean "few". I live in Seattle, which has one of the better transit networks in the country, certainly better than average. Yet, 85% of households own cars. In the suburbs, that percentage is even higher.
> Also, suburbs are boring as hell. There's literally nothing to do outside except stare at parked cars and locked houses.
That hasn't been my experience. There's lots of things to do in suburbs, you just need to drive there. The rest of your comment is about some difficulties of doing walks in suburbs, which are quite foreign to me -- for one thing, I'm quite sure that almost everywhere in Seattle metro area, you're not more than 1 hour walk from a convenience store. Given how millions of people love going hiking in places even further from convenience stores, gas stations and water fountains, I don't see this as such a huge problem. The rest of your complaints are simply matter of your preferences: I for one thing couldn't care less about presence of places to walk into and explore. I'm not a tourist in my own town, I need to get places and get things done, and idly walking around the business districts is not one of my hobbies.
This may be a US thing. I've lived in about 10 countries now (but not the US), and I hardly knew anyone who owned a car in any of them.
That can be hard for Europeans to wrap their head around. (I live here and am a car enthusiast and it’s hard for me to wrap my head around.)
In the USA registration wildly varies by state and the actual stat is a quarter billion "vehicles" but in my state every non-rowboat boat is a registered vehicle (although essentially unenforced for small sailboats and inflatables) and every boat trailer is yet another vehicle and every RV is a registered license plated vehicle and every trailer and etc. My parents never owned more than one car although they had five "registered vehicles" at one point. Also any commercial vehicle that drives on public roads, in my state this includes SOME farm tractors and other farm equipment. Needless to say every motorcycle and moped is a registered vehicle, and in my municipality, resident bicycles are technically required to be registered although never enforced.
Nationwide there's about 70M "things that move and pay registration tax and are not cars" that are registered as vehicles. Very near one per adult.
As a check on the figures, note there's only 105M "housing units" in the USA, so when you see strange figures reported about 300M to 400M vehicles its obvious that the average house does not have four cars parked in front of it, and that figure includes scrapped cars in junkyards and railroad cars and minecarts and things like that.
Don't you have towns and villages in the US?
Are you European by chance? We have these things but they tend to be very spread out due to our wealth of land, especially so as you move further west. Further a lot of them have basically slowly turned into boring suburban sprawl.
Active urban space, sleepy suburbs, and country-living are pretty much your options in most of the US.
Many people who live in urban areas neither own a car nor want to drive.
Also, suburbs are boring as hell. There's literally nothing to do outside except stare at parked cars and locked houses. Taking a walk for more than an hour is impossible because there is nowhere to go to the bathroom, unless you want to do your business in someone's bush. There are no drinking fountains, and if you get hungry on your long walk, you're screwed. It can get (seriously) depressing, compared to cities, where most of the stuff you pass by on the street is generally open to walk into and explore, and food/water/restrooms are readily available.