But there are things like health insurance which Uber would have to provide (and in the contractor case, are instead subsidised through Obamacare provisions) that I think would end up with take home being less...
Obamacare mandates access to insurance (from a dwindling group of participating insurers), it is not a direct subsidy.
In fact, Obamacare has raised insurance rates for most people, as insurers cancelled most plans because they "were not compatible" with Obamacare, and re-enrolled members at higher rates than before.
Health insurance might be more of a problem, but this is really only a US issue.
I am wondering if a franchise model (say like McDonald's) might get you to a model where you have the benefits of employees, but without all the associated issues.