When you look at how little has changed from the 2016 to 2017 Chevy Volt and how promising the Tesla Model 3 is, one may ask why would anyone buy 2017 Volt and not Tesla Model 3. While Chevy Bolt is more promising vs Tesla Model 3, the 2017 Volt has it's own advantages.
Chevy Volt is a great car for slightly different purposes and needs than Tesla Model 3.
First of all, it can Act as a pure electric car for most people, most of the time. With this, it can run also 400+ miles. After that the Volt can be completely refilled in minutes.
Tesla Model 3 Pros
The opponents of Chevy Volt, say that Tesla Model 3 ownership empowers will empower them to envision similar and maybe better interior in Model 3 than the current Model S. They also expect top notch engine performance. They expect Model 3 to be a very good car. The prototype looks very promising and the production model shouldn't change much. 400.000 did not experience it yet and still made an order to purchase the Model 3. I wonder how many will order after the Model 3's second unveil.
2017 Chevy Volt Pros
Volt proponents also say that the car is available now. In fact, apparently the demand for the 2016-2017 Chevy Volt has increased significantly. People want to lease, so they don't have to buy it and take the risk of inevitable depreciation of current cars (when you lease you pay for depreciation upfront). Many people apparently do this as they wait for their Tesla Model 3 to be delivered in a year or two.
Also, supercharging is an issue for many people. If you live in rural area and don't have superchargers nearby, Chevy Volt is your car to use. For most people it can be electric 90% of the time.
Since supercharging is not everywhere, the Volt has its place right now. At the end of the day, a car is a personal choice. Comparing the 2017 Chevy Volt vs Tesla Model 3 may work for someone and may not work for the others. A lot depends on your geographical location and unique driving habits.