You seem to be completely unfamiliar with the research in the field. It is well known that controlling for socioeconomic factors
does not substantially impact predictive validity of standardized tests. See for example
https://journals.sagepub.com/doi/abs/10.1177/095679761243873...
> Scores on the SAT (a test widely used in the admissions process in the United States), secondary school grades, college grades, and SES measures from 143,606 students at 110 colleges and universities were examined, and results of these analyses were compared with results obtained using a 41-school data set including scores from the prior version of the SAT and using University of California data from prior research on the role of SES. In all the data sets, the SAT showed incremental validity over secondary school grades in predicting subsequent academic performance, and this incremental relationship was not substantially affected by controlling for SES.
Or this
https://eric.ed.gov/?id=ED562860
> (a) SES is related to SAT scores (r = 0.42 among the population of SAT takers), (b) SAT scores are predictive of freshman grades (r = 0.47 corrected for school-specific range restriction), and (c) statistically controlling for SES reduces the estimated SAT-grade correlation from r = 0.47 to r = 0.44.
There are more studies on this, with rather consistent results. In short, poor students do about as well as rich students when matched on SAT score.
https://journals.sagepub.com/doi/abs/10.1177/095679761243873...
> Scores on the SAT (a test widely used in the admissions process in the United States), secondary school grades, college grades, and SES measures from 143,606 students at 110 colleges and universities were examined, and results of these analyses were compared with results obtained using a 41-school data set including scores from the prior version of the SAT and using University of California data from prior research on the role of SES. In all the data sets, the SAT showed incremental validity over secondary school grades in predicting subsequent academic performance, and this incremental relationship was not substantially affected by controlling for SES.
Or this
https://eric.ed.gov/?id=ED562860
> (a) SES is related to SAT scores (r = 0.42 among the population of SAT takers), (b) SAT scores are predictive of freshman grades (r = 0.47 corrected for school-specific range restriction), and (c) statistically controlling for SES reduces the estimated SAT-grade correlation from r = 0.47 to r = 0.44.
There are more studies on this, with rather consistent results. In short, poor students do about as well as rich students when matched on SAT score.