That’s easily affordable with one income, with a family making the median software developer wage. Any competent developer can pick up the phone, call a few local recruiters and have three or four offers in three weeks. Of course the pickings get slimmer the further to the right of the bell curve you go. But I do know developers who have been a lot more aggressive about their career a lot longer than I have and usually takes them two or three months to get jobs over the 80th percentile.
I picked $135K because that’s a pretty easy mark to hit if you have any negotiating skill, keep your eye on the market, and keep a warm network.
$160K+ is doable as an architect or an overpriced consultant working for a consulting company.
Which is to say - the finances are only one part of it! Living in a large city is qualitatively different from living in a small city which is different from living in a rural area. If you have a strong preference, giving up the best financial situation to live the life you want is super reasonable. I know plenty of people who could live more comfortably in a cheaper area, but some people just want to be in a big city. I'm sure the reverse is true as well.
None of the cities I listed are in what you would consider rural America. Yes we live in the burbs, but if living in the city were the lifestyle we wanted, we could buy a smaller condo for about the same price and I could still have access to the same job market.
On the other hand, if you can't get one of those top positions in the Bay you're probably looking at closer to $150k-$200k in a senior position, which makes a $100k or so low CoL position look awfully nice.
This gap widens as you go up the salary scale. I don't think I've ever seen even $300k in a low CoL area, whereas in the expensive areas 7 figures is possible (although quite rare).