The whole point of objectivity is that it allows for cooperation and understanding between people with different experiences. People can invent whatever ideas they like, but by testing those ideas against an objective physical standard, it becomes possible to determine which one is more correct. Without that, when views diverge, people default to stuff like "might makes right."

Critical thinking is a process of examining and questioning of one's preexisting beliefs, through rationality. Without that process, what you have is either the ideas that you have passively absorbed through society (primarily, the ideas of the ruling class), or your own made up stuff that other people have no reason to agree with, leading to an inability to unite around an alternative and a de facto victory for the status quo. Subjectivity is not true freedom, because it leads to division and confusion, and division is incapable of resisting oppression, "For what force on earth is weaker than the feeble strength of one?"

It's such a pet peeve for me the way you're always trying to tie the validity of trans identities to a rejection of objectivity. Trans rights are objective! It is factual, testable, observable, that supporting trans identities has a positive effect on people's mental health. In rejecting objectivity, you are, in fact, opening the door to say that subjective perspectives that are transphobic are just as true as anything else.