Waste of time, huh? You have differences in IQ between black, hispanic, white, and asian americans leading to very big differences on, say, standardized math and verbal tests. Now, the teachers are accused of racism, because their black students are scoring much lower than their asian students. Then they are judged unfairly and put into the impossible situation where they are expected to graduate students with no test score differences between races, because no one is willing to admit that there are IQ differences between races, which means a series of weird evasions where schools have to stop administering objective tests, or hide the results of the tests from the public, or go through ritual handwringing about "systemic racism", "unconscious racism", "undetectable racism", because these racial differences remain across time, cultures, and even nations, and seem stubbornly resistant to any intervention other than one involving no longer collecting the data, or no longer reporting the data.
Or, we can just accept that there are differences in IQ which should lead to differences in test scores and normalize correctly. That would be useful. It would not put teachers into impossible situations. We would not be tying teacher pay to impossible to achieve goals.
But no, we can't honestly approach this subject and must constantly contort everything because honest baselines and metrics would be a "waste of time" over the unrealistic and impossible to obtain outcomes.
Same with incarceration rates, and some other group differences. Oh, wouldn't you like to know which group differences are biological and which are due to the shared environment, so that we know which interventions have a chance of working and which don't? No, we can't know that, as obtaining this information would be a waste of time. Honesty would also stop enormous wastes of human capital being currently spent on simultaneously trying to cover up differences in outcomes as well as punishing people arbitrarily when they notice said differences.