It's really not out of reach unless you insist on living in a major metropolis. A young couple earning under $100k combined can afford a comfortable 3-bedroom home in all 50 states, just not in a large city. Mortgage rates are near all-time lows and the 20% "required downpayment" has been a myth since before you were born. You don't even need great credit to buy a home with a mortgage under $1500/mo all-in with taxes and insurance. Now that remote work is increasingly accepted there's never been a better time to buy in the suburbs.
People go where the jobs are. They are going to live wherever employers "insist on" locating their offices.
20% down payment isn't a myth; if you don't put 20% down (and don't have some special situation like a VA loan) you have to pay for private mortgage insurance which can be hundreds per month, as you're buying the lender insurance against the possibility of you defaulting on your loan.
Depending on your situation, PMI may be worth it. For example I was paying 1200 a month for a 1 br apartment. They wanted to up it to 1500 a month. Instead I bought a house with 5% down. The total monthly payment for a 200k house, including PMI, is 1,100 a month.
Even with PMI I am still paying less than living in the same apartment year over year.
PMI is reasonable. I put down 5% on my first home, (<$20k) and commuted via train. Just get a cell modem and do your morning work rituals (email, news, etc) on the train. I sold that house 3 years later at 13.5% appreciation, with good equity on top. I used all of that towards the down payment on house #2.
Commute in from a small investment home/condo to let equity + appreciation get you into the home you want a few years down the road. Even in my starter, I got twice the sqft for the same monthly as my not-very-close apt.
$100k? A quick google shows me that median household income in the US is closer to $60k. And that's the median, so half of households will be lower than that.
I imagine those in the Bay area are making a lot more than 50k/year, or at least there are always SV devs chiming in saying they are making 300-600k/year (the OP said 100k for a couple).
I make the equivalent of 100k USD in a tier 2 city in Scotland (a single income that is, not a couple combined). It's not outlandish for senior roles across much of the UK (with "normal" companies, not FAANG).
Yeah, dude, there's a site "Levels FYI" that gives real data. If anyone's having trouble wrapping their brains around it, just keep in mind that every business needs to send a sizable chunk of its revenue through Silicon Valley to stay competitive (via advertising, office equipment/software, apps, etc)
100k is attainable even in the middle of nowhere in the USA, but you'd probably be better off working remotely for someone for 120k+
New CS grads start off at like 120k. New boot camp grads start off at like 100k. If you're experienced, you might get up to 200k. If you're experienced and good, you can hit 300k and beyond. Once FAANG sets the standard like this, then basically everyone else needs to offer similar salaries if they want to compete for that same quality of engineer.
It seems a reasonable enough assumption to me, that tech workers make more than average - so much so that I didn't feel the need to trawl for a peer reviewed data source.
It was a somewhat-arbitrary line. $60k/yr is about $3k/mo takehome. While that's not a lot of money, it's enough to live a modest lifestyle including a mortgage and raising children with only a single parent working. I'm not saying it won't be a struggle, but it's doable. It's how I was raised and it's how most of my family lives, and I'm in NJ, which is in the top 10 most expensive states. My niece and nephew-in-law live comfortably on $70k with two kids, two cars, one earner, and just bought a house. Life is hard and that's ok.
30-34 is stretching the definitions of a "young couple", of course. I'd love numbers for 20-25, but this data set lumps in 15-24 all together, though the set of married couples under 20 is presumably pretty small.
After all this, for many people I suspect that living in the core area of an "elite" city is going to become a luxury lifestyle decision rather than at least a perceived cost that is part and parcel of desirable jobs. Some will still choose to do so, but it will be the same sort of expensive optional choice that living in a trendy beach or mountain town will be.