Gender dysphoria is a clinical condition where a person believes he/sheis born in the wrong body.
Our sexual identity is 100% dictated by our brain. Well there is such a thing as a female brain and a male brain. It happens sometime that someone with male physical characteristics has a brain structure that is closer to a female brain and the other way around too.
Gender dysphoria can manifest itself very early in children. In some few cases, a child that exhibits signs of gender dysphoria before puberty will stop showing those signs during adolescence when the brain gets rewired into an adult brain. Most will continue to exhibit sings of gender dysphoria.
The objective of a sane society should be to allow children to act in the way that makes them comfortable until the changes of puberty confirm or infirm the feelings of dysphoria.
There should not be any opposition to boys being allowed to dress as girls and use the girls bathroom or girls to act as boys. The crushing majority of pre-pubescent children almost never have an externalized sexuality (meaning the need to act sexually with a partner), children's sexuality is one of self-discovery and curiosity.
The curiosity part of pre-pubescent sexuality is usually quite benign and too often reprimanded or criminalized is some parts of the world. Wanting to see how the other boys or girls are made is quite normal and is part of a child learning about him/herself. Of course there can be exceptions but those have other environmental factors like previous sexual abuse but remain quite rare.
Thinking about the sexual development of children makes everyone of us uncomfortable and many of us would prefer to ignore it or to pretend it doesn't exist. But this can be detrimental to the development of the children.
Nudity is not the same as sexuality
Exposure to casual nudity (not pornography) seems to create better adjusted individuals. Heavy repression of nudity and of acceptable sexual expression tend to create more cases of rape and of sexual violence.
Exposure of children to nudity in the family circle and in acceptable public settings such as the beach helps them learn that a human body is NOT what you see in pornography. It helps create adults who are more accepting of their own body and who are less prone to mental disorders such as self-hate, eating disorders and the lot.
Letting children learn about the human body through pornography seems to create abnormal expectations that, when unmet, can lead to violence, depression, hate and self-harm.
Children will find ways to learn about nudity and sexuality, no matter if you want them or not.
Our societies are still too immature to understand how our disdain for nudity is causing us a wide range of problems. Nudity and sexuality are not "dirty", they are natural and part of being a human.