Or the best phrase ist: there is no point in generalizing literally half of human population.
And the point with confidence is more that it makes your whole life easy(not just dating) - since you are just not really afraid to fail no matter the odds, but it’s really difficult to develop as an adult.
Confidence is difficult to build all of your life, not just as an adult. It wasn’t really a problem with “girls like” but more the “just don’t be insecure” connotations
As a child it’s basically your parents supporting and believing in you (helps being good at something). As an adult it’s being really good at something and working on your childhood trauma of not supportive parents.
I don’t really get your point - since not being insecure just helps generally in life. And it’s always good to work on ones insecurities - be it just for oneselfs peace of mind.