An interesting thread! Peaking, for me, was of a somewhat different type, beginning (more than a decade ago) with my understanding of feminist theory which clearly implies that the origin of women's subjugation is in sex, and that gender roles, rules and stereotypes have been ways of contributing to that subjugation.
So if 'woman' would suddenly be defined as something not based on being female, feminist work would pretty much lose the language and the data that is relevant for improving the lot of women in this world.
Someone smart on Twitter used the parable of cats and dogs:
Everyone understands those two groups, how their needs etc. might differ in veterinary medicine and so on. If we were suddenly told that the group 'dogs' now consists of all dogs except dachshunds but also includes Siamese cats, and the group 'cats' now consists of all cats except Siamese cats but also includes dachshunds, writing about dogs and cats in veterinary medicine or laws about keeping pets etc. would become impossibly complicated.
I couldn't see how any feminist would not see this, so I thought that the work feminism was doing would not be affected by trans rights (i.e., that no trans activist would demand, and no feminist would agree to, the erasure of the female sex from language and the deconstruction of the female body into various parts).
In a sense that belief in peaceful coexistence was the more academic #bekind approach, and there are still many, many feminists trying to straddle the paradox of being in a movement which is based on combating sex-based discrimination while prioritising male transitioners' goals, and while also prioritising the feelings of those women who choose to identify as something else.
My proper peaking happened when I realised that I had been completely wrong!
That was a truly dark time, Watching the events unfurl online made me feel as if I was watching a natural experiment in one of the ways women may have historically become second-class citizens, that complicated mix of different incentives and different types of obliviousness, the unconscious tilt towards taking male concerns more seriously, the willingness of many women not to have firm boundaries, the rise of the Karen trend, the desire to be 'good' etc. And this made me question to what extent women could ever retrieve any of the things we were rapidly losing.
So the after-peak era for me has been based on the radical acceptance that all this is taking place, even though it's not a progressive development, and to keep on arguing for more evidence-based and nuanced conversations and the importance of the rights of all people, not just some.
I have seen the term The Age Of Endarkenment used to refer to various political movements of the recent decades (Trumpianism, radical Islam, increased authoritarianism and political polarisation all over the world), and this phenomenon belongs to that group. Distancing myself in these ways has helped me.