To learn more, read about hypergamy: https://en.wikipedia.org/wiki/Hypergamy
TLDR: All women seek higher status males, inevitably leading to the highest status males reproducing with more females.
Being a multimillionaire is not 'higher status' when it comes to meeting women (unless you make it to the hundred-millionaire state')
Being a founder or a corporate exec is not 'higher status' when it comes to meeting women (unless you are C-suite at a fortune-500)
While I think this sounds very true, do you have a reference?
It completely matches the experience in the city I live in, and I'd love to be able to quote it to people.
OKCupid has some research, but they don't record actual sex encounters. They have stats like "As you can see from the gray line, women rate an incredible 80% of guys as worse-looking than medium".
Hooking up stats are rather clear: around 80% of women have sex with around 20% of men. That's why an average looking guy on PoF/CL/Tinder/OkCupid has very little chance compared to real life.
This imbalance is actually caused by the guys. Your average guy will throw himself at almost any woman. You join a site, you go through profiles, you message the ones you like. You can easily message 100 girls and get 1 reply. Why? Because every other average guy is doing the same. So an average girl gets 100 messages a day, and there's no way she's replying to all of them - she will pick the top 5-10, and will talk to them.
If your face isn't good looking, don't worry. You can compensate with other things. Hit the gym, girls LOVE fit bodies, even though most of them you tell you they want someone funny/smart/interesting. Don't believe the words, believe the actions. When I started gaining muscle, women started paying attention. Other things that help are: confidence, ability to speak calmly and confidently, dressing better than average, treating women as humans, not as princesses.
If you want to meet lots of women IRL, pick up an activity with mostly women, like dance, yoga.