Lot of reasons 1) apps like Tinder, bumble, etc make it VERY, VERY easy if you are a 9 or 10 man to find someone 2) so many forms of birth control/protection 3) stigma is nearly completely gone 4) ability to remove or treat STDs is up a lot from 20-30 years ago etc
Have you ever noticed that the STD’s seem to stay ahead of the treatments for them? Make one treatable, there’s another one soon enough. Such behavior is a disease vector. Always has been, always will be. A loving God didn’t forbid promiscuity because he’s just a big meanie who doesn’t want us to have any fun. He forbids it to protect us.