this essay hinges on the fundamental misunderstanding that something being a social construct makes it "fake". copying from wikipedia:

A social construct is any category or thing that is made real by convention or collective agreement. Socially constructed realities are contrasted with natural kinds, which exist independently of human behavior or beliefs.

you seem to use the term 'social phenomenon' as a replacement for 'social construct' without a clear definition for it. is the distinction only in that a 'social construct' is a social phenomenon constructed for the sole purpose of oppression?

Firstly, Gender is not a social construct. It is however, a social phenomenon, but so race in this regard. However with race, we call it a "social construct" because it was constructed (by intention) to discriminate people and support colonialist ideas. Gender on the other hand, would not be considered as such because while gender is a social thing, it is not a thing which was constructed to artificially oppress people.