You guys don’t understand electric propulsion. You can’t compare it to ice engines.  
While the EV is always efficient the ICE engines masks its huge inefficient use of fuel by dividing its power into gears - which is greatly reflected by the loss of acceleration. It is as though you know it is happening but you refuse to understand it after all these years of shifting gears. Maybe it’s because I drive a manual.  Lol. 
If you added gears to a Tesla for more range it would have zero impact other than the extra weight.   A taller gear would simply add more resistance and cause more electricity to be used at a lower rpm. 
Perhaps the biggest benefit for the Porsche is that drive line components are less stressed with the lower gear off the line.  But if you think it help speed or mileage you need to seriously hit the text books. 
Of course it takes longer to charge for now but it you travel less than 250 miles at a time you actually spend less time fueling or driving to a gas station.   If you have electricity at home. Lol. Some still think that this electric stuff will not ever make it to the home.