Yes. If we had infinite money, infinite time, and the ability to put people into stasis while we tear up entire cities to retrofit them for a train system… that still wouldn’t solve the problem.

Cars haven't existed forever and we managed to build places around them. There's no reason we can't start building everything new around other modes of transport.

If you live in a city, you are done. If you live on the outskirts of a city?...

I live in Switzerland, and none of the problems you mention in the next few paragraphs exist here. I mean frequency of public transport isn't as good out of the cities, but I can get a bus or train to pretty much anywhere a car can get to, and some places they can't. The buses are nice and work well, they have priority in the city so they don't get stuck in traffic. I can get train, tram, bus, or bike to the airport no problem and if I need something bigger than I can carry I'll just get it delivered. Yes Switzerland is rich but there's a lot of money to be saved if it wasn't being spent on cars, car infrastructure, and all of the externalities of driving. It's also small, but our trains don't go particularly quickly.

Even then, the vast majority of people in developed countries (and the majority worldwide) live in urban areas. If the people living in podunk towns need to drive, power to them. Focusing on urban areas will have a bigger impact.

But unless you are rich enough to live in the city center, you are still going to deal with a lot of headaches.

And the alternative is being rich enough to afford a house in the suburbs AND a car for every member of the family? Walkable doesn't have to mean the city centre, and it's much easier to achieve if you don't have to kowtow to a bunch of suburbanites who want to drive their SUVs through your neighbourhood.