If someone is experiencing pain, mental agony due to them feeling they are physically the wrong gender - this must be incredibly traumatic. - Yes it must and I am very sympathetic to anyone in mental agony or experiencing trauma. But my opinion is that they should receive sympathetic treatment to accept themselves as they are.
All of us have male and female chromosomes, X & Y. Whats interesting is in nature, gender is not rigid - animals/ species change or flip btw gender - yes this is true, and as a biologist I agree very interesting. However humans as a species don't flip sex so this argument is irrelevant here.
We humans have created a rigid concept of binary gender - which isn’t based on facts. - yes we have and I believe rigid gender stereotypes are indeed harmful and have contributed hugely to the mess we're in currently. Biological sex however is binary and not a "concept" humans have created, but a biological fact.
why can’t we allow others to live their lives in ways they want - I agree as long as it doesn't infringe on the rights and safety of others
it isn’t causing any harm. - it is actually, biological women and girls have been harmed by this,
There seems to be some hysteria about men in changing rooms - I can’t recall prior to a few years ago anyone really getting up in arms about this. - as a woman I find the term hysteria offensive so you might want to consider not using it. Nevertheless women and girls have very valid reasons for being concerned about men in women only spaces. A few years ago men weren't generally allowed to use women's changing rooms so no it wasn't an issue. However if you go further back to the 1970s feminists fought very hard to get single sex spaces for women.
I struggle with why all of a sudden this issue has become to talked about. - it's not all of a sudden, it's been talked about for years, but women were not listened to and labelled terfs and bigots, so many were too intimidated to speak out.
It’s strange and has a whiff of scapegoating and finding ways to create “otherness” - really? Isn't the concept of "non binary" creating otherness? The CG movement is actually doing the opposite of creating otherness!
rather than wanting to embrace diversity and live together peacefully - I'm sure most women would love to live together peacefully, shame there are so many violent and abusive men around
accepting others as they want to be accepted - most people do, it's just that increasing numbers of people draw the line at accepting that humans can change biological sex