Gay rights was always about asking people to accept reality, namely, that there are people who have sexual orientations other than heterosexual. The idea is that sexual orientation is pretty much proven to be part of someone's immutable biological makeup. This has led to overwhelming acceptance.
Trans "rights", on the other hand, are premised on asking people to deny biological reality. In some cases, people can do that. If a man in the People's Front for the Liberation of Judea wants to be called Loretta, then we can out of courtesy respect that request. Once that man wants his balls waxed, or wants to be able to compete in women's sports, we've crossed a line and have to come back to reality.
Deny Biological Reality sounds kind of arbitrary for much of life is assigning a new reality over an old one. If we did not do this (assigning a new reality over an old one) than we would merely be passengers experiencing reality that the fates decreed.