Thinking a lot about how a lot of transphobia is rooted in the misogynistic idea that a woman's role is to reproduce and submit to her husband.
It manifests itself in different ways, but they all share the same root.
For transphobia against trans women, it manifests as transphobes blasting trans women for "immigrating" womanhood and telling trans women that they'll never be real women because, ultimately, they don't have a uterus and can't become pregnant. Trans women who have vulvas are told that their vulvas aren't "real", even if their vulvas can fulfill every other aspect of a vulva except for the processes involved in pregnancy. Trans women's existence challenges the notion that a woman's worth is measured by whether or not she can become pregnant and submit.
For transphobia against trans men, it manifests as transphobes fear-mongering about trans men "mutilating" their bodies, especially their "female" organs like breasts, uterus, and vulva. They fear-monger about testosterone, saying that it'll render anyone who takes it infertile, as if becoming infertile is worse than a trans man taking his life because he can't transition. Not to mention that testosterone doesn't render the taker infertile. Trans men who elect to remove their breasts and get a hysterectomy are further demonized as abandoning the principles of womanhood- becoming pregnant and being desirable.
If it was truly about concern about infertility, then why do trans women not face the same scrutiny for the way estrogen may affect the testes and penis? It's because one uterus can only produce so many babies while one penis can fertilize a nearly infinite amount of offspring. It's about the commodification of reproduction- transphobes don't care whether trans women can reproduce or not because they don't need them spread their "undesirable" seed- but trans men are seen as women by virtue of their uteruses and thus must continue to be controlled.
Trans women challenge this system by insisting that they are women even though they cannot become pregnant- they force the people in power to reckon with the reality that many women, regardless of their assigned sex, cannot or do not wish to become pregnant, and have been suppressed for this for so long.
Trans men challenge this system by placing their own value over the value of their fertility- by asserting that their mental and physical well-being is more important than their ability to become pregnant. They force the people in power to reckon with the reality that many people do not wish to become or remain pregnant, that to become pregnant would be detrimental to their well-being.
Non-binary people challenge this system by refusing to submit to the rigid classifications of "man" or "woman", and all the expectations that entail with those roles.
People hate trans people because our very existence threatens the fragile definitions of gender and gender expectations that exist to uphold a patriarchal system.