Adcoms know faculty.
I’m assuming you want stem. T20s usually have a stem ctontact who’ll also review select promising apps. A handful.
Personal contact is more about the prof calling admissions.
When speaking of T20 schools, it’s the applicant’s responsibility to learn as much about the college, get an idea of what it seeks. What rounding. Depth and breadth. Attitude, energy and more.
And to understand what holistic is. It not just being in stats ranges. And/or research. They’ll read your whole app, looking for their idea of match.