As I see it, the most strident critics of standardized testing have come right out of the belly of the beast of inequality such as Steven J. Gould. It's not accidental that they combine the support of rich donors with racist tropes (e.g. we're doing this for Black people because they're stupid) and unfortunately too many of the left eat it up.
The dynamic range of wealth and power is that one family can have 100,000 times or more wealth than another family. That dynamic range is compressed by a controlled environment like the SAT test: all the wealth in the world can't raise your score by more than 30% or so. If anything, a poor kid has a chance of showing what they are worth on a test like that whereas some rich kids can't test their way out of a paper bag unless they outright hire a ringer to take the test for them -- giving a badly needed form of downward social mobility.
Putting focus on the SAT helps to further obscure the real methods of "achievement laundering" by which rich kids can turn their family wealth into the illusion of accomplishment and leaves those unexamined... In the name of equity!
