How much weight does the SAT hold in regards to Ivy league and top college Admission?

Wouldn’t the general rule for any super-selective school be that one has to stand out in some way and have no “defects”?

It is rather difficult or impossible for test scores to make an applicant stand out at a super-selective school, since they get lots of applicants whose test scores approach the maximum possible. But it is certainly possible for a lower test score to be a “defect” that will lead to rejection, at least in the absence of something even more exceptional than is usual for admitted applicants.