You just want to murder people and have people pat you on the back for it. The cancer I see is bigotry, because unlike trans people, it is incompatible with society. It spreads and evolves like cancer at the cellular level, taking more and more resources and causing more and more suffering. Eventually, the oppressed will strike back, leading to war both civil and international. Because war has become so destructive, these tensions risk total annihilation of entire societies, cultures, and even the human race.
It's a societal cancer that lives in your brain, but unlike real cancer, it can be destroyed without killing the cell. You can reject it and become a good person who doesn't kill people for fun. You just have to choose.
Our life is meaning less, we come and go, so I think the most important thing we can do is to make the time here as pleasant as possible for everyone. I don't see how your suggestion could prevent suffering. On the contrary, I think it could even lead to more.