"Shit" is an overstatement. If a nice car and insurance is 15k, rent is 1500 bucks a month (so 18k a year), and groceries are 10k a year (and that's double the average), that's a total of 43k a year. Add in health insurance for what, 5k a year (if you're making 90k, insurance shouldn't be more than 400 bucks a month)? 90k yearly is ~67k a year after federal taxes. After all of the necessary expenses, you're left with 17k left over. Student loan payments probably cut into that, but that's still a significant sum of money. This is especially true if you can cut that rent down, or don't drive a super nice car, or have a smaller insurance payment through your workplace, etc.
That $17k surplus assumes that this person will be doing nothing remotely fun with their lives. Add even a modest amount of travel, movies, reataurants, bars, etc., and that money disappears quickly.
That's only 17k net a year left over before savings, travel, or restaurants.
Going out to eat almost anywhere decent is a hundred bucks these days.
$1500 a month is not a reasonable assumption for monthly housing overhead even in a low CoL location. Also mortgage interest rates are much higher now.
If 1,400 a month for non-necessities isn't considered good, I struggle to see what a reasonable definition of "good" is.
1,500 is perfectly reasonable for a low cost of living area. I currently pay 1,800 a month (and that includes electric, which also powers my heat) in a state that most consider to be one of the highest costs of living in the US. For that amount of money, I could be renting a standalone house in much of the country.
I also think that your assertion of going out to eat costing 100 bucks is inaccurate. Many decent restaurants have entrées in the 18-25 dollar range. Add in a beer and an appetizer, plus a 30% tip, and you still only hit 65 dollars (assuming the app/entree cost 40 bucks combined and the beer costs 10, which is a high estimate).
All of this also assumes that you drive a nice car, a luxury that most wouldn't consider a necessity. The 15k number assumes 1250 combined for car payments and insurance, a number which many would consider much too high.
Is it the most glamorous life? No. But calling it "shit pay" is a massive overreach. If you can afford a solid car, your own place, all the necessities, and still have 1400 bucks to play with, I would consider that a pretty solid life. Certainly above "shit."
$100 for one person eating out?? I feel like even at a nice sit down place in San Francisco when I visited late last year I was paying much less than that.
In low cost of living / mid cost of living (LCOL/MCOL) areas you can definitely eat out for two at a decent place for less than that. Pricing out for two at my favorite local Italian place in San Antonio, here's the bill:
$15 - spaghetti with homemade meat sauce
$16 - penne arrabiatta
$20 - wine
Pad 28% for tax and tip and you come out to ~$65.
On San Antonio Zillow, I'm finding almost 200 results for 2 bedrooms at $1200 or less per month.
I don't think San Antonio is even the lowest LCOL location you could find, by far. Even in Texas, not looking outside the state, El Paso's way cheaper, maybe Corpus Christi.
I think people often overestimate how much it costs to live quite well in a LCOL area.