If your baseline for living includes owning two luxury cars that you store in a private garage, a brand new luxury apartment, shopping exclusively at Whole Foods, having maids clean your house and take care of your children, and sending your kids to elite private schools, then yeah 250k a year is basically poverty. Life as an engineer sure is hard.
Eating out at a restaurant that isn't a taqueria or in-n-out is about $20-$30 a person at the low end. A drink at a bar will set you back at least $6, and probably more like $12-$15. Getting your one-bedroom apartment cleaned once a month will cost you about $100-$150.
I don't have children, but not-rich friends who do have told me that unless you live in a "good" neighborhood and/or your kid can be bussed long distances, you really have to consider paying for private schools, and that's something like 20k a year, per child.
So one-bedroom, one car of parking (not counting maintenance or the cost of the car), eating out at a modest place once a week: $3500 + $200 + $320 + $120 = $4140/mo. That's frugal. Want a kid? Dramatically more.
While $250K is certainly a comfortable level for a single person, it is not as outrageous as it may seem to people outside of the really high-cost areas in the US.
To have a salary of $250k means that you are well off, in fact I seem to recall that being the cut-off for the 1% range.
The top-end engineer salary of $160k doesn't go very far here, right now. I'm sure that the distance it goes feels like a lot when you're 23 and one foot out of the dorm room, but when you get older and start wanting to have an adult life (children, saving for retirement, maybe buying a place), it isn't even remotely enough.
$250k, in San Francisco, will rent you a market-rate, one-bedroom apartment ($4k, until they raise the rent next year), and let you live a pretty good lifestyle as a single person: you'll have something like $10k per month after taxes. If you're frugal, and don't go out much, you can get by on maybe $2k a month in expenses. That leaves $8k to save, invest, spend on children, etc.
We aren't talking about big, glamorous lifestyles here.