There definitely is a correlation between constituent family income and school "quality", sure, but the actual experience is still overall better (will tend to

There definitely is a correlation between constituent family income and school "quality", sure, but the actual experience is still overall better (will tend to be, anyway—please take any of these generalities as statistical in nature, not absolute) if you can get into those better-due-to-selection-bias schools. A lot of the same things that make kids in poorer schools harder to teach also mean more classroom disruption and worse peer models, which do harm the experience and outcomes for kids in those schools, even if they are from a stable household without money trouble and the effort & expertise that goes into instruction is identical. That selection bias thing is part of why it's so damn hard to crack the problem of evening out (while, ideally, improving the average of) school performance—but when I'm wearing my parent-hat and not my speculating-about-public-policy-I'd-like-to-see hat, it's hard to conclude other than that paying attention to which schools are "best" is still a good idea, even if the reasons are a bit bullshitty.