The single biggest problem is that people spend too much time online now, particularly from a young age. Not only does this prevent them from meeting in-person and experiencing physical chemistry with others, but it also develops all these bizarre social behaviours and norms that make people anxious and cautious when they meet offline. It's no surprise that people, especially younger people, are not having sex when you look at how they behave online. They are so passive aggressive and hostile by default - they don't trust anyone because the constant fighting being pushed to them through algorithmic social media has conditioned them to think every other person is a dickhead or is going to betray them somehow. You need to be willing to get close to people and be vulnerable with them to have sex, and they aren't.