Toxic masculinity and how we raise boys in society is what needs to change
I agree with that. I think that society does judge boys who are 'different' and imposes strict rules on them - especially with how they present to the world.
I do think that the dysphoria associated with some trans people and the efffectiveness and relief that HRT and surgery brings to how the body looks and feels is different though and cannot be ignored.
I do think that something biological is going on there - whether it's how the chromosomal expression is affected by hormones in the womb, during development, epigenetics - because chromosomes are more than X and Y etc.
I think that does not have to mean 'lady brain'. It just might well mean that something has happened that means the XY expression has been affected and that's caused an effect somewhere in the brain to make a trans person see that their body is 'wrong'. I know some people will dismiss that - but as someone said upthread, the brain is incredibly complex and there are many things we don't know about it. Gene expression is incredibly complex, Hormones are complex. Epigenetics is a new science.
The feeling of body dysphoria cannot be ignored , its causes are very unclear and the feeling of relief that is felt as the body becomes more what 'it should be' should not be under estimated. To call it 'mutilation' is to dismiss what is a life changing operation