I have heard AOs say that a writing sample done while interviewing is pretty much all they need. They point to kids who came in with terrible test scores (less than 50%) who headed off to Harvard 4 years later. Fluke? Who knows.
That same AO also always asked interviewees lots of questions about how they handled homework. Whether she was right or wrong, the underlying assumption was that a hard-worker who had evidenced decent writing and reasoning skills (in that writing sample) could be a good student.
But I also agree that a test can be a good equalizer. I will say this - if you admit a ton of super high-achieving students, you probably don’t need high quality teaching. They’ll work it out. If you admit more middling students, the teaching needs to be top notch because this cohort needs it. There’s a part of me that wonders how this will play out for schools. To the extent that they admit students who need “more” to succeed, how will they do?