That is a pretty simplistic approach to the social influence on transgenderism.
Sexuality and gender identity exist on a continuum and are not binary. Like anything on a continuum, social influence plays a significant role in how people choose to identify.
Let's assume that the transgender scale goes from 0-10, with 10 being someone who has always known they were born in the wrong body and never identified with their assigned at birth gender, and 0 being someone like Zen Mode.
If someone is say a 6 or a 7 on that scale and they live in rural Alabama, they are much, much less likely to transition than if they live in Marin County. When people see their friends and family members transitioning, and their social media algorithms extolling the benefits of transitioning, that unquestionably will influence the decision to transition. Of course, it doesn't turn a 1 into a 10, and it likely doesn't change the underlying psychology of a person, but it certainly influences the decision to transition.
And this is true with any identity, be it racism, homosexuality, religious views, political views. The identity we take on is very much influenced by our environment. That is not to say there is not a biological component to identity. Of course there is. And it is often the predominate influence. But environmental factors also play a very significant role -- especially for people that are in the middle of the continuum.