I hired a few ghostwriters from Upwork to write short semi-technical whitepapers and the results were extremely disappointing. Even American writers with impressive resumes and multiple 5-star recommendations, who charged a hefty hourly rate (which I would have been delighted to pay them, over and over, if they'd been any good), produced completely unacceptable garbage, despite being provided with detailed outlines and extensive guidance.

I don't know whether my experience is relevant, but there it is.