Young people are having less sex

Well of my 3, the youngest is in a committed relationship that started in college. One doesn’t date at all and doesn’t use online apps (I asked) and he assumes he will find someone sooner or later but doesn’t and won’t put any energy into looking. The oldest just said bye to an on again off again gf of 8 years he met in college. I asked him why and he said she can’t commit to the relationship and is a flake so they all have sex…one more than the other two I am sure. All 3 are attractive in a classic all-American type genre and have college educations and good jobs/careers so who knows. I suspect the two older ones will eventually end up with younger women at this point in their lives as they approach 30 and beyond or they will find someone late when the young couple divorces start happening as I am seeing that now with friends 30+ unmarried males.