In most cases, we'll take an outline from a business owner along with a style guide they produced or had produced by their agency, and choose a writer as close as possible to their industry. You can't fake insider knowledge, but you can transfer the details and have a great writer build in the details.
Maybe a better analogy is like a head chef and his souz-chefs. Our clients create the recipe, but our writers prepare the dish.
How is an outsourced writer going to draw on someone else's experiences?
A blog written from real experience may be valuable. A blog pretending to be written from real experience is worse that worthless for the readers.