Wealth is relative. "In the bay area" is absolutely relevant. Companies in SF pay so much because the cost of living is so high. Someone with $20 is not richer than someone with $10 if it costs the first person $15 to buy lunch and it costs the second person $2 to buy the equivalent lunch.
I realize that cost of living has an impact on wealth.
But, we're talking about taxes and mostly about a couple specific provisions: SALT deduction, mortgage interest deduction, and the higher-end tax rate. Relative wealth is definitely not relevant to the SALT and mortgage interest deductions. (To review, the mortgage interest deduction subsidizes the rich and the SALT deduction forces people in low tax states to subsidize people in high tax states)
The only one left is tax brackets. You could argue that tax brackets should take into account cost of living. So, if you earn 100k in Nebraska you'd pay a higher percentage of that than a similar person living in SF. But, I think that doesn't take into account the fact that SF is such an in-demand place to live. You don't have to live in SF. Basically, I'm not convinced that cost of living differences should play a role in taxes.