Either I am vastly underpaid or the numbers are very high for newer developers. Even with 0 experience and 0 skill, it quotes $86k.
They appear to have a decent entry pay but not scale very well as you go up from there. As an example: it shows for an SRE with 10 years experience and a 5 for skill, a salary of $145,400.
Stackoverflow is largely based out of NYC, so their salaries are going to be based on that starting point.
The average developer salary in the US is $80K but when you start going state by state you can see that NYC/California/et al are throwing that figure WAY off.
Of course, if you're trying to raise a big family, the math works out a little differently.
Looking at the average for that around here being £20K, I'd suggest it's really well off the mark unless you're in Silicon Valley.