Uber also had a proven market. Taxis existed for about 400 years before Uber was created. Gig jobs also existed before and mostly seemed to suffer supply issues

Uber also had a proven market. Taxis existed for about 400 years before Uber was created. Gig jobs also existed before and mostly seemed to suffer supply issues (not a lot of flexible work available), leading to lots of scams in the area. Like Dropbox and AirBnB, Uber brought some improvements for customers, but demand was well established.