It started with John Money and his 'success' in persuading David Reimer's parents to raise him as a girl and reporting this as a good outcome.
By the time David was aware that his case had been reported as a success when it had been a miserable failure for him, the case study was so well known and other medics could see the potential for experientation, and it was too embedded to be unembedded.
Drugs [which are the same ones that were used to castrate paedophiles and gay men in the historical past], were already being used to delay puberty in kids who were having early onset puberty.
A clinic put two and two together and trialled this on teens with 'gender dysphoria'. And when they assessed the teens after this treatment, they switched the questions to the ones that would have been asked for the opposite sex, and clapped themselves on the back for doing such a great job. They failed to really study the actual physical effects on these people, or on the older people who had 'sex reassignment surgery' and called these practices, 'The Dutch Protocol'. This has been followed throughout the world as the best way to treat what they are now calling 'Gender Incongruence'.
Meanwhile the lobby groups piggybacked on Gay Rights, and a group of Gay Rights Campaigners met in Yogyatarka, to discuss 'where next' in gay rights, and a few TRA campaigners arrived and hijacked the meeting to shoehorn in Trans Rights. And a set of principles were born.
Elsewhere one of the biggest men in Trans Rights, who is a multimillionaire funded the world's biggest legal company to create a document on 'how to embed unpopular causes into policy' which is called the Denton's Document. They looked at 'best practice' in countries where getting 'trans rights' into law had been successful, without a care obviously for any fallout of that law [aka issues with the rights of women and kids]. I cannot say what this man's motivations are, I'd get a ban.
Whilst the lobby groups were busy getting visibility of trans people, as shown by Hayley Cropper etc, and the likes of Stonewall ran out of things to lobby for [as gay rights were now in law] they needed a new funding stream and this was their new thing, and those who were getting voted into committees etc, they began rewriting the rules and policies, piggybacking on 'Diversity, Inclusion and Equity'. Partnered up of course here with other social rights movements in a typical 'forced teaming'.
Also, before gay marriage was legal, a man who said he was a woman took the British Government through the European Court of Human Rights for the right to marry his long term partner. And the Gender Recognition Act was created. It allowed him to marry another man.
Also the likes of Susie Green who got puberty blockers for her son, because her husband didn't want a gay son, and took him to Thailand to have his [by that point tiny] penis removed and inverted for his 16th Birthday. She then went on to head up Mermaids and had huge influence over the GIDS Clinic at The Tavistock, including getting them to overturn doctors recommendations and pressure them to transition kids.
By then of course the huge behemoth of the medical industry had seen a market for lifeling customers, and this has been pushed at every level ever since. Including getting into schools to indoctrinate kids younger and younger. See also 'Debbie' Hayton who force teams everyone and their dog, who wrote the policies that erased your kids' rights to single sex toilets in schools, but who is now forced teaming themselves with groups that are trying to turn the clock back. How anyone cannot see this is beyond me.
This is not a bottom up movement, it is a men's sexual rights movement supported by the multi billion $ USA and worldwide medical industry and has infiltrated everywhere.
It ain't going away any time soon.