men aren't necessarily meant raise kids, they're meant to pass on their genes. those are 2 very different things. i don't really know if leaving behind a legacy is a man's purpose, at least not all men since not all men are exceptional.
in fact from an evolutionary perspective, all orgasms shrare the exclusive goal to pass on their genes. the importance of parental investment in the offspring depends on the environmental conditions, etc but in general males are not the ones who typically care about investment in offspring since they have the ability to pass their genes on to many different females, which negates any need to invest in one particular child, it's a different strategy entirely.
in the modern day this is no different. if a man wanted to, he could go raw dog a dozen women in southeast asia or just visit a few sperm banks...
Your theory matches perspective that was still open only to some kings in XVIIIth or early XIXth century (or similar persons) and is no longer valid. Nowadays, with raise of social media HQ men easily get trapped in relationships to the point they are raising other people offspring willingly because being that "openminded" is expected from them and is part of their social image (imagine biological fathers of adopted Brad Pitt's or Tom Cruise's babies having laughs on the thought that their children have pretty much guaranteed future now when Kidman/Cruise or Jolie/Pitt take care of them.
Pumping&dumping freely w/o consequences of taking care of babies is pretty much not available to anyone anymore (tbh it qas always ostracised if someone's position was reputation-related). If HQ man with high social rank will try to do that, his reputation will be tarnished or he will even face jail (Prince Andrew case is a good example).
FYI: You live in the world where your former GF can file rape report out of jealousy even years after relationship ends and she can inform other people about it through social media; in the world where you can be thrown into jail because you are not paying alimonies - in the world where clients of brothels/prostitutes are recorded and later blackmailed if there is a point to do so and they are stupid enough to leave enough crumbs to be identified).
Social media, technology and awareness of society is very high these days and all these help guard social order or help people that are below other people to get something from people above them (legally or not) - sometimes its much better to not act on your urge to sleep with a woman than to actually do it - especially in Western countries/USA.
Notice how many celebrities try to keep their life private, especially if they are dating much below their own age. You have only one reputation - and its much more valuable than carnal pleasure.