The key word is might. I was commuting in a big city, 1+ hour one way, regardless car or public transit. So you'd think that in the latter case I had 40-50 minutes to do stuff? Wrong. First you need to wait for the transport, technically you can read something quickly while waiting, but you always need to watch for car numbers, not to miss yours, and holding a phone out in winder is fucking cold. In summer sun blinding a screen and causing it to overheat due to max brightness. Then you are riding in the overcrowded tram or bus, one hand holding the rail not to fall, so no typing, and reading is rather limited when you are packed like sardines. Then you repeat all that for the second leg of the trip (not many are lucky to have a direct line to work). So all in all out of 1 wasted hour you maybe read for like 10 minutes total in shitty conditions. Oh, and reading standing really hurts your neck (because you are reading face down), spine (because you are always in the asymmetrical stance), and hand (carpal syndrome from holding too wide phone and doing swiping gestures with the same hand).
Commuting in the car obviously makes impossible to do anything else.
Total efficiency of commute is about zero.