"Cost of living" factor is the most idiotic thing ever.
Also, cost of living adjustments should only be applied to subsistence-level, locally-priced expenses (i.e. rent, gas prices, fresh groceries, etc.). You don't want the $X you are putting into savings every year to be adjusted down because you moved to a cheaper zip code.
If the formula for salary was (basic expenses * life factor) + (benchmark * role * experience) I would understand, but we're nowhere near that.
It's more complicated than that, too. The average NYC rent is higher, but the average NYC apartment is also smaller. And the average commute for a SF employee is longer. Let's say you're in a three bedroom townhouse with a garage ten minutes from work in Austin. Is the COL adjustment going to pay you enough to have a three bedroom townhouse ten minutes from work in SF?
Also, COL is more local than the city. The rent in Jackson Heights, Queens is a fraction of the rent in Chelsea, Manhattan.