We've been playing games with education in the US for a while now. This identity stuff is the newest, but you can go back every decade or so for some 60 years and find some fad that was really big at the time.
Now look at the test scores over time. Up? Down? Flat? Break it out into race, socioeconomic class, religion, however you want. Check again. Up? Down? Flat?
We pretty well know how to teach things like math. It's a lot of drills. It's a lot of homework. It's word problems. It's all the things that both teachers and students hate, because it's annoying to do and annoying to check. But math is more or less like learning a language. You have to immerse yourself in it and do a lot of practice.
And, in the end, you have to accept that some people are just not going to cut it. They will top out at about 8th grade basic Algebra. And that's okay! Cramming some kid who can't cut Calculus into a Calculus class just because you need to count a certain number of different colored noses is daft and unproductive. School should educate people to their maximum ability, and everybody's maximum ability is different.
It doesn't matter if it makes you feel better to attribute somebody's poor performance to some vaporous societal ill. That's not helping. That's trying to shoehorn your preferred reality into actual reality. The hell of it is that it completely shafts those who really did earn their way into the top ranks. There is always the spectre that they're there because some administrator needed enough $IDENTITY to make their Powerpoint presentation look good.