Many people work for multiple jobs at once. I've been a receptionist who codes for someone else at the same time, and I've been a crowd manager while doing email for my other job. Both were time sheet W2 employee relationships.

This isn't about computers whatsoever. This is about the requirements and business relationship between Uber and Uber drivers. The relationship does not allow Uber drivers to subcontract, negotiate prices, and had control over profit and loss. Uber drivers are employees.