Uber's endgame is to roll out globally with an attractive platform for users and an enticing offer for drivers, gain a dominant market share in as many markets as possible, then steadily replace all human drivers with self-driving cars. This will happen over the next several decades.
At that point, the company will maintain service centers for their fleets, whose maintenance costs will be low enough to significantly increase their profit margins. Those larger profits will, of course, flow to the relatively small number of shareholders instead of being distributed among a larger human workforce, as they are currently.
Listen to Peter Thiel. The endgame for superlative companies is monopoly.