That's true, Fennel (and thanks ? )
If it were down to medical advances, though, there would have been a lot of children in times gone by who were desperately unhappy, and I don't remember that being the case. Unhappy gay people, for sure, but I really don't think that there were legions of people 'just knowing' that they were 'born in the wrong body'. I know that a lot of people always (whatever the cause of their unhappiness) suffer in silence, but the way 'some people' talk, this has been an issue since time began, and there would have been clues in Art, literature, drama, something by now, if that were true. Also, it would have impacted on at least some powerful people, who would have been able to do whatever they liked (and did, in many ways), but AFAIK there is no suggestion that the occasional lord, duke or king 'lived as' a woman.
I think the social atmosphere just now is toxic, the, and agree with you that there is a lot of 'just put up with it' from certain quarters. There is a veneer of 'be kind', but it is used to make passive aggressive digs at people who don't conform, and to squash questioning. I think the term was coined in response to tweets about the late Caroline Flack, and whilst I'm not at all advocating malice on social media, I think 'be kind' has now morphed into something that means 'don't criticise anything that a self-appointed set of people have decided is right'.
It tends to be used to silence women - maybe men are less likely to be concerned about having a 'kindly' reputation? Also, it has always been the case that women are called 'bitchy', if they say things that would be considered witty or incisive if a man said them - 'be kind' is yet another tool of the patriarchy, and yet another way to stop debate in its tracks.