My son likes competition math and we commuted to a middle school where there were many kids that also enjoyed AMC's and other academic competitions. DS took AP Calc BC in 9th and we initiated the AMC 10 and 12 at his high school and there is very little interest. I think he found 5 kids for the 20 spots we had.

Similar story with Mu Alpha Theta...the school did the first and third tests but forgot to do the second one.

DS spent significant time trying to locate middle school kids in our area to teach competition math (he gave up on high school kids) and we found two that were family friends. Luckily they seem to enjoy it and plan to get the AMC 8 offered next year at their school.

We live in a high-income area where the majority spend time on sports, not academics.