You intervene when the student is still learning the material, before the test.

You do not intervene after the test. At that point the learning process for that material is already over. The student has already "missed out" on the learning opportunity. You would just be giving a good grade to someone who doesn't know the material.

Yes we need to help folks who are intergenerationally poor. But, you do that by helping their kids learn better and meet the testing bar.

You are not helping them by lowering the bar for them. Giving the kids better grades even if they don't know the material, would actually hurt them.