I do not know france, but for example in India smart drivers who do that all time, use uber as lead gen tool for regular recurring customers like office going employees, senior citizens with regular hospital visits and build relationships offline and network just like any good freelancer.

But it's different than literally every other employment opportunity right? No one flips burgers at McDonalds and runs across the street to make a taco at Taco Bell and then runs back to do more burgers at McDonalds all in the same hour/shift.