What I don't see discussed here is that we are reaching peak employment in the United States so part time jobs will swap out in favor of more stable employment.

What I don't see discussed here is that we are reaching peak employment in the United States so part time jobs will swap out in favor of more stable employment. I would predict an increase in the number of "gig" jobs as employment regresses back to the mean and/or if we see another spike in unemployment. Rephrased as a question: "Did these companies succeed primarily because of the job / capital market they grew up in, or was it just a contributor to the scale / growth?"