Yeah, it’s not as complicated as that. You can make some cozy psychology excuse such as that to try and make yourself feel better about it - but it’s really just as simple as it feels like sex, and we have sex drives for reproduction.

Just look at apes, other primates that do it too – they aren’t doing it to be “confident in their sexuality” etc etc. It’s literally just that it feels good.

There’s only 1 instance of masturbation that I know about, that scientists think is an evolutionary advantage – and that’s of rats that masturbate, and they tend to do it after mating; scientists believe that this came about in order to reduce the instance of sexually transmitted diseases by clearing the male rats of foreign material.