Totally different experience than described above. The most selective colleges & universities in the country are heavily into recruiting from poor schools. Hold multiple fairs which are heavily advertised in public media & in all public & private schools.
Conversely, my child went to a super elite private prep school & the college counseling was worthless. We fired his assigned counselor & did not use the head of counseling who took over (who just offered admission to a very top LAC). Really did not need any college counseling as already had full ride in hand when the senior year began.
But at the top elites, the parents push the kids & the counselors try to get students to apply to colleges that few have heard of. Over 30% matriculate at Ivies, however.