There is an argument to be made that the SAT does reflect college readiness, and it is the lack of opportunity that drives down POC and female college readiness. So in a sense the test is not flawed, but simply measures the underlying inequality. See the thoughts of Freddie deBoer.
It should come as no surprise, then, given the SAT’s racist origins, that since its inception, poor students, Black students, Hispanic students, and Indigenous students have consistently received scores on the test that are double-digit percentages lower than white students. And that SAT scores have long been recognized as poor indicators of actual college readiness. Given what we know about society’s biases and how the scales are always tilted toward people in power, it was inevitable that a test that so clearly showed favor to wealthier white students would be eagerly adopted by schools seeking ways to keep their percentages of wealthy white students high, and their percentages of poor students and students of color low. In disadvantaging poor students and students of color, and in advantaging white students more for their race than for their actual college aptitude or readiness, the SAT test has always worked as designed. — Mediocre, pg 93