It's illustrative of the wealth divide in our society that engineers think 96th percentile wages are middle class.
Also, cost of living needs to be applied to these numbers, 100k in the Bay Area is 65k in Florida is 45k in Georgia.
Affluence is about how much you can afford relative to the rest of your society. If you're only comparing yourself to San Franciscans and New Yorkers, doesn't that mean you don't consider the flyover Americans your peers? As if there were some large divide in wealth in this country?