Why are you acting like this is completely outside the realm of possibility to impact? If fewer women want to be with a man or live with a man because of how that negatively impacts her life, the solution - helloooo - is for men to become the sorts of real partners most women want (and rarely find). Of course a lot of men want to be married - married men are the happiest demographic (and married women are the least happy).

If the only reason you want children is to "leave a legacy" I highly suggest that you never have any. Children are people with individual needs and wants and not mini-mes to be used as props in your personal life scenario. They require an enormous amount of time and attention and are largely highly inconvenient and messy. Unless you're also embracing that aspect, don't even think about having children.