[kochb]

The exact growing conditions for olive production aren’t common in the US, so most of the production comes from California - west of Sacramento and south along the San Joaquin river. There are a lot of barriers in bringing specialty crops to market related to know-how and contracting sale of product, so even in other areas where growth may be possible it may be infeasible.

https://www.agmrc.org/commodities-products/fruits/olives

https://croplandcros.scinet.usda.gov/

[Yeul]

I mean if you could make olive oil cheaper in America wouldn't someone have done that by now?

The US never lacked for smart entrepreneurs looking for a business opportunity. See wine.

[newyankee]

Most likely the answer in many such examples is it needs cheap human labor. US seldom lacks anything in terms of natural resources and always comes down to this.