In the earlier days of the tranny movement taking off, they were absolutely not synonymous and were in fact in a civil war similar to the current LibFem vs TERF one.

Trenders wanted trannyism to just be a personality quirk they could use for attention and AGP, similar to "self diagnosed" mental afflictions where as "truscum" (as they were called) believed it was a medical condition (gender dysphoria).

The trenders won, got gender dysphoria discarded as a thing entirely, and then pretended it was always a singular solidified movement.