"Researchers... looked at the 100 most populated metropolitan areas, analyzing data from before and after the introduction of Uber and its competitors"

Fair inquiry, but no. They studied the top 100 metro areas, not the Podunks. Now, it does not say whether the rate has remained steady despite, perhaps, an increase in people who now feel comfortable getting drunk cuz they can get a cab fairly easily with the intro of ride services. However, they have not decreased the totals, as they have claimed, according to the findings.

Uber doesn't launch in areas where there isn't a market. If there is no need for extensive taxi and mass transit services, Uber won't be there either.

I maintain that Uber is just another option in the top 100 metro areas. If Uber did work everywhere, then I am sure you would see reductions in places that do not have competing services.

No. As someone who has gotten a DWI in one of the largest cities, I drove my car because I wanted to an was an irresponsible idiot, not because I had no options.