Doing so enough times will lead to Uber penalizing the driver. Does that sound like a freelancer to you?
Obviously, the definition will change depending on the country. Referring to a previous court case UK (Employment Tribunal: Uber BV v. Aslam), this is why they think Uber drivers are employees, not freelancers:
> Uber set the fare which meant that they dictated how much drivers could earn
> Uber set the contract terms and drivers had no say in them
> Request for rides is constrained by Uber who can penalise drivers if they reject too many rides
> Uber monitors a driver's service through the star rating and has the capacity to terminate the relationship if after repeated warnings this does not improve
With those things in mind, it's hard to not feel like Uber drivers are in fact employees of Uber, not freelancers that can freely engage in business while only being "supported" by Uber or using Ubers app.