Amazon, Uber, PostMates, UberEats, and the trucking industry love the gig economy because it shifts a portion of the salary back to the laborer.

Suppose you have a salary of 40K per year. It probably cost the company around 60K if you include the rest of compensation such as medical. Amazon wants to make a one-time investment in you in order to shift that cost to you for all time.

A broken arm costs 50K. Medical insurance is easily 1K per month. Have a couple of employees? The temptation is also to gig them (Amazon gigs you, you gig your riders).

Amazon is the master of shifting costs from themselves; more likely they have done their homework while us (the entrepeneurs) will by trial and error figure out if this work.