Mind activity. The activity of problem solving, organizing thought, taking decisions - when e.g. you mentally organize your time, you actively problem solve. With the listening, you are processing information, which is different. A lesson in mathematics is radically different from solving mathematical exercises.

But one is all for optimizing time and if you find that meeting information e.g. while driving works well for you, comes natural and fruitful - that is just excellent!

Also, there are the mental breaks, which are necessary part of the whole process like phases in breathing. I am not sure the car is optimal for them though.

All three things have their space.