Not sure where they live, but I live in Vermont, and you asking about numbers and got me thinking. I had not done the math on our recent purchase of a Mach-E.
Old car was a 2016 Mazda CX-5, on a good day it averaged 27 mpg. Gas is currently $3.99 here, so that is 6.766 miles/$.
On the new Mach-E we get about 200 miles per charge and the battery is 91 kWh. We pay $0.18/kWh for any time charging (normal rate for energy here), which comes out to 12.21 miles/$. If we charge off peak it is $0.13/kWh and moves that number to 16.9 miles/$.
Not included most of the time is that you are always leaving the house on a full charge, no more using your time to travel to a gas station. Which is about 10 extra miles each way for us. Also no more oil changes. So the real savings number is higher