And gametogenesis research has been advancing rapidly recently, so it probably won't even be that long. One can do stem cell->gamete and successfully create offspring in mice https://www.gwern.net/docs/genetics/gametogenesis/2021-yoshi... and there are already startups to try to do it for humans: https://www.technologyreview.com/2021/10/28/1038172/concepti...