for something to awaken itself, it has to be dormant or resting to begin with. So Rey HAS to have the potential for those great and powerful things within herself all along. Not everybody can have that, or else everybody would be walking around being OP in the Force. There’s a reason Ben calls Luke their “last hope”. They can’t pluck some random dude off the streets of Tatooine to become a Jedi. There HAS to be a genetic factor here.
Sure, something about Rey is special…but it’s not her genetics, at least according to TLJ.
As Maz says, the Skywalker blade called to Rey. It didn’t call to anyone else in that pirate den, over all the years it had been there. So yes, Rey may have had worthless nobody parents and the latent potential to be a Jedi, just like thousands of other people from across the galaxy who were discovered by the Jedi Order as children, children who presumably had normal parents.
There really doesn’t have to be a genetic factor here.