Apparently Model 3 has a low total cost of ownership/operation per mile - i.e., popular for Uber for the same reason a Prius is popular for Uber.
The Model 3 is ridiculously expensive. Base price RWD $47k. You can get into a Prius for $25k. At 58mpg there will never be a breakeven for the Model 3. Economics will be different with this upcoming $7,500 tax credit, but that obviously doesn't apply to any current owners.