The state sets lower limits to what work should be worth, in order to avoid unpleasant social outcomes, such as worker abuse. It also sets a minimum of benefits companies should offer, in order to fulfil their side of the social contract - being allowed to safely do business and have access to capital, workers, etc.

If Uber, or any other company invents a type of work which cannot be compensated according to those rules, then they do not have a viable business and will go bankrupt or be fined out of existence.

In practice, they've managed to find enough loopholes to survive, while making the lives of many of their employees miserable.