In my opinion, yes sex means a lot in life. But it's not the main goal in life or the purpose of life directly. When you're getting old sex start to mean less. You start looking at your life and see if you had lived a good life. Have you been a good man. Have you done everything you wanted/could. And do you have people around you, that you can share you thoughts, memories, feelings with.
This is the whole point. It is never the direct goal. It's transcendence into everything that gives meaning is.
Rather, everything that we perceive as meaningful has stemmed from functions that promoted reproduction and gene preservation.
it goes full circle.