The screenwriters’ strike that began last May, and the actors’ strike that followed in July, highlighted an employment model that has given Hollywood a highly flexible workforce for decades: The vast majority of people on a set are not studio employees but independent contractors or employees of other firms. Take, for example, the people who worked on this year’s Oscar winner for best picture, Everything Everywhere All at Once. In addition to the 42 actors; the 49 artists, set dressers, and painters; and the hundreds more who provided art, music, transportation, writing and editing, costumes, casting, sound, and stunts, the rest of the crew came from six production companies, three special-effects firms, and 28 other organizations.