There's an article about a woman who replaced her car (well, SUV) with Uber and how much money she saved. A lot of the variable costs were from her commute "from home to KP in Menlo Park was 70 miles round trip and I’d go down to the office 2–3 times a week." That's quite the commute to do by Uber.
She spent $4700 on Uber last year.
The cost of an Uber from Sand Hill to San Francisco is $51 to $68, without any surge. An average roundtrip would cost $120. So if you did this two to three times per week for a year it would cost $15,000. It's pretty clear that she's not replacing Uber trips with car trips, or she wouldn't have made it to May. So without a car, how does she get to Menlo Park?
By train, of course. Caltrain runs a nice service south from the City, with frequent trains, many of them express. She uses Uber on either end (you know, there are these bike things, and buses, but those are hard). So there's probably an $8 Uber ride on either end, and the other $104 are on Caltrain (40 minutes, generally faster than traffic). Except it costs $13.50. So the whole commute costs $30, or ¼ of the cost of riding Uber both ways, all of the savings from transit.
Taking Uber both ways would cost 50% more than driving. So that doesn't work. What she really means to be saying is "I started taking transit for the majority of my commuting miles and saved a ton of money." The Uber use helps the transit work in this case, but it's Caltrain that is the main reason this works, not just Uber.