Uncapped stimulation and convenience. A typical month may look like this -

  - Manhattan rent: $2k-$4k (depends if you are sharing or living alone)
  - Not cooking: $1-1.5k ($5 lattes, $15 salads, $20 meals, x 30 days)
  - Socials & drinking: $1k (~$150 x 4-6 per month)
  - NYC events: $1k (gigs, comedy clubs, festivals)

Young professionals with established careers do not move to NYC to think about how much they could save if they lived in Tennessee instead. The narrow focus is to soak up available opportunities and maximize revenues, instead of minimizing costs. It's a risky gamble.