From your cite:

>Based on our main findings, along with the above summary of the general habits of people who use rideshare services, the data seems to suggest (emphasis on “seem”) that many rideshare customers are opting to hail a ride home after an evening at the bar or club, rather than risk driving intoxicated.

This is what people have historically done when they are drunk, it is not a new behavior invented by Uber.

It's not what people typically did because taxis were not generally available in most US cities. You couldn't rely on a taxi coming to pick you up at your home nor rely on one being there when you wanted to leave.

Nevertheless there are other options, such as calling a friend, taking the bus, walking, etc. It's not clear that Uber resulted in people who would otherwise have been drunk drivers instead calling a cab. People who drunk drive presumably don't arrive at that choice because of a minor inconvenience.