I mean, it's targeted manipulation of pressure points in human psychology. If it never worked, they'd adopt different unethical tactics.

That said, I think you overestimate the level of churn those guys are willing to go through. They'll strike out a lot in rapid succession, burning through the local pool of women until they find one that falls for their gimmicks. When you're willing to take dozens of rejections and settle for anyone moderately physically attractive, yeah, it's easy to keep someone around, just not easy to keep the same someone around.

Yes, manipulation often works on people who don't know what that looks like yet, like young people.

Plus people who do this stuff know what sort of targets to look for. They intentionally choose vulnerable people with whom the strategies are more likely to work. It’s not that this shit works universally on women.

I don't really think women "flock" to these types. Part of what they teach is how you shouldn't care about rejection, so those types end up asking/harassing a lot more women.

Say you are in a competition with someone to get as many job offers as possible. The dude handing out his resume and hounding the recipients all day and night is going to get more job offers than someone selectively applying for jobs they want. That doesn't mean the dude harassing people is going to get a good job, or have it very long, but that's not what they care about.