This gets brought up a lot, but in (all? most?) US states the additional state and local funding that goes to low-income schools more that makes up for the decreased local property tax revenue. That manifests as a negative correlation between affluence and per-pupil spend, and (at least in Ohio where I grew up) a negative correlation between per-pupil spend and various measures of academic success.

I wish people would look up the data on this sort of thing before confidently making claims.

https://apps.urban.org/features/school-funding-do-poor-kids-...