> Humans overall will eventually cease to exist. All of us will be forgotten within a few generations, even if we have children. Motherhood/fatherhood is not the "real end game of life." You might believe so, but many others do not. Why are their points of view less valid than your own?
It's the end game of life in the sense that your goal in life is to achieve immortality. Pretty much all of our ancestors did this by mating, and within the past 500 years you're likely to be able to find the names of all who came before you on ancestry, which is effectively immortality in name. Irvin Yalom once said, "They say you die twice. Once when you stop breathing and the second, a bit later on, when somebody mentions your name for the last time" (this quote was not from Bansky).
For those that don't, or didn't reproduce, immortality is so extremely hard to achieve. That's why I mention "increasing Google's stock price" - it doesn't matter, and nobody will remember your name for doing so. You'll leave a good life, but that's it. The only way to achieve immortality in this case is to leave a legacy. For example, Steve Jobs is slated to leave a legacy for as long as Apple is alive plus perhaps a thousand years or more. Of course, once humanity is wiped out, it won't matter all too much what anyone did or ever will do, save for all of the species of plants, animals, and insects we've extincted.
It's no secret that money, i.e. capitalism, is one of the biggest factors why millenials and soon enough Gen Z will avoid starting a family. A lot will do it for financial independence but the amount of married couples that also forego children is likely large. For all of them, they won't leave a legacy if they don't create the next Apple. If that's not important to them, I respect that and wouldn't wish to force them into anything, but many married (or prospective) couples are having their dreams crushed by how infeasible it is becoming to financially support children without both parents working a job.