GPA is also much more subject to getting penalized because a teacher straight up hates you for being poor, disabled, male (this one is measurable by having teachers grade tests with different names), ugly, smelly, other thing K-12 teachers tend to dock you for even though on paper they shouldn’t.

Many extracurriculars are also expensive and poor kids don’t get to do a lot of them or excel at them to the same degree.

The only exception I can think of are the temporarily poor; e.g. refugees from Southeast Asia or Africa whose families were well to do back home and still have that familial knowledge even if they are currently lacking in money.

Extracurriculars I agree with, rich people are more likely to have connections to get the nice internships.