Divorce is horrible for sure but that is mainly down to interpersonal relationships.

It is a simple fact that unprotected sex with large numbers of people is very risky. We should have learnt that lesson in the eighties.

If there's somebody out there advocating for "unprotected sex with large numbers of people", you should go post at them, because I don't see that here.

The biggest barrier to disease transmission reduction, at least here in the US, is uncritical abstinence promoters like yourself. It works, at best, for a small fraction of the population, and leaves the rest woefully unprepared for the biological realities. The best solution to STDs is education. Which, yes, should emphasize that not having sex is an option, but cannot stop there.