They could hire W2 employees right through the app, there is no technical barrier.
Uber just wants to avoid their fair share of payroll taxes and employee health regulations that their upper caste office employees enjoy. They want to provide benefits to some employees but not all, purely based on their job description.
I bet your ridesharing gig worker friends you know would love no longer covering the full payroll tax bill, and they’d love to be covered with workers compensation if they got into a car accident while driving for Uber.
If companies don’t want to pay for healthcare and benefits anymore, maybe they should start putting their lobbying efforts toward making healthcare paid through tax revenue rather than through the inequality and inefficiency of employer subsidy and for-profit private insurance companies.