Trans - particularly amongst males - has become a full-blown craze in the current century, for the reasons you cite. But it's not the case that it suddenly arose in the past 20 years. It's mushroomed and become widespread and dominant in recent years, but the seeds were being sown over the course of many decades.

I don't doubt you when you say that in the 1980s,

never once did I hear anyone say "I was born in the wrong body" or "I'm really the opposite sex."

But that doesn't mean no one was saying these things back then. Some men were making such claims for many, many decades.

In the 1950s and 1960s, a former US military man who went by the name Christine Jorgensen became a huge celebrity in the Western world for having undergone what was then called a "sex change." When Jorgensen died in 1989, the NY Times said

Miss Jorgensen said she had a normal, happy childhood but on growing up became frustrated by feelings that she was a woman trapped in a man's body.

https://www.nytimes.com/1989/05/04/obituaries/christine-jorgensen-62-is-dead-was-first-to-have-a-sex-change.html

Yeah, [in the 1980s] you'd hear about a RARE "sex change" operation in some other country or HSTS, but there were no Riley J. Dennis, Charlotte Clymer, Brianna Wu, etc. types. None.

In the 1960s & 70s in the Western world, the idea of males having "sex change" operations got a lot of coverage in the mainstream press. Whilst Christine Jorgensen appears to have been HSTS, the two biggest TIM celebrities of the 1970s - James Jan Morris and Richard Raskin Renee Richards - were both conventionally "manly men" who'd excelled in macho pursuits and careers who "transitioned" in mid-life after being married to women and fathering children. Like AGPs today, they called themselves lesbians after their surgeries and only had sexual/romantic relationships with women (Morris actually stayed with his wife after the two divorced).

To give you an idea how manly these two men were: Morris initially made a name for himself by writing of his travels alone in places off the beaten track in the Muslim world, and by being one of the men who climbed Mt Everest with Sir Edmund Hillary. Raskin/Richards attended male-only HS and university where he excelled in men's sports, including American football. Then he did a stint in the (male) military, where he continued to excel in male sports by being one of the US Navy's top-ranked men's tennis players. Raskin/Richards also went to an American medical school at a time when there was a cap on the number of women allowed to study medicine and get MDs in the US.

Conundrum, the memoir by Morris about his "sex change," was a huge English-language bestseller after it was published in 1974. In his memoir, Morris showed enormous male entitlement, sexism and misogyny. Yet Morris was widely celebrated for "changing sex."

In 1976, Richards sued in NY courts to be able to compete in US women's professional tennis - and won. Suing for that "right" seems very much a "TRA" move steeped in male supremacy, sexism and high-octane misogyny to me.

Gore Vidal's novel about a man who became a TIM due to medical "forced feminization" Myra Breckenridge, came out in 1968. In the movie version, this TIM was played by Raquel Welch - fueling men's fantasies that if they were to become women, they'd all of course look exactly like one of the hottest Hollywood female sex symbols of all time.

John Irving's The World According to Garp, a worldwide publishing sensation in 1978, featured as a main character Roberta Muldoon, a TIM who'd formerly been a famous NFL player. In the movie, to the casting director's credit, Muldoon was not played by a gorgeous woman like Raquel Welch, but much more realistically by John Lithgow.

In the 1960s and 70s, tons of gay male transvestites and heterosexual cross-dressers (in the mode of Grayson Perry and Eddie Izzard) were around. Which is why The Kinks's song Lola became such a hit when it was released in 1970.

In the 1950s and 1960s, transvestites and cross-dressing men hadn't yet seized enough power to become the/a dominant narrative in popular culture and political circles like today. In fact, they were scorned and derided. But they definitely were there. Everyone knew this, which is why no one blinked an eye over Norman Bates in the 1960 movie Psycho. And it's one of the reasons audiences in the 1950s found the film Some Like It Hot so funny and the character of Corporal Klinger in the TV show MASH so funny.

These and the large number of other popular TV shows, skits and of the 1950s-80s that featured "female impersonators" took behaviors everyone knew that some males did in private settings for sexual arousal and made them public - and in so doing, caused such behaviors to be publicly ridiculed as well as looked at with sympathy at the same time.

In the 1960s and 70s, a change began to occur. Starting first in hipster and avant garde circles and then spreading to the wider culture, men who engaged in transvestitism, "transsexualism" and cross-dressing began to be considered ultra cool and cutting-edge: Candy Darling, Lou Reed, David Bowie, the NY Dolls, glam rock.

Moreover, throughout the 1960s and 70s, the political movement behind male transvestitism, cross-dressing and "transsexualism" - all of which IMO are part of, and ultimate expressions of, the larger project of male libertinism - was indeed prominent, powerful and gathering steam with each passing year.

BTW, the father of my school mate's was an AGP who "became a woman" and started calling himself a lesbian in his late 40s in 1974. This wasn't happening all the time and being widely celebrated the way it is today, but it was going on.

For more history, I highly suggest reading Janice Raymond's The Transsexual Empire which was published in 1979. It's free on her website.

But several things that are happening today are indeed new and have cropped up only in the past 20 years or so as you say. These include: a) the concerted effort on the part of adults - parents, educators, the mainstream media - to indoctrinate children into gender ideology and strict sex stereotyping starting in infancy; b) the profusion of "childhood gender clinics" and "gender therapists;" c) the practice of sending children whom adults view as liking "the wrong" toys/clothes/manner of play for their sex to gender clinics to get them put on punishing, extreme medical pathways to change their bodies to better suit the strict sex stereotypes that adults have taught them to embrace; d) the trend of seeing all the attention-seeking, sexist and homophobic parents intent on transing their kids as "progressive" and "loving" rather than as regressive sexists committing child abuse in plain sight; e) the current fad for "changing sex" amongst female children, adolescents and young adults that's caused and is causing so many girls and young women to revel in - and preach to others - the toxic misogyny they have unfortunately been steeped in growing up and have internalized as self-hatred (and hatred for female people and being female) as a result.

Regarding how the craze for going "trans" started becoming popular amongst young lesbians in the US in the 1990s, I highly recommend Ariel Levy's 2005 book, Female Chauvinist Pigs: Women and the Rise of Raunch Culture.