> For the very last example, we have a 28-year-old man, earning well below average in NYC (90k a year), who nonetheless saves $2,000 a month. I'm sensing a bias here.

$90k a year is definitely not "well below average in NYC" - median household income is only $70k a year! (1)

1 - https://www.census.gov/quickfacts/fact/table/newyorkcitynewy...