Yes, a scooter is smaller and takes fewer resources to manufacture but cars routinely go 120,000 or more miles while the average scooter will be lucky to see 10,000 miles. Some scooters go “kerplunk” at a few thousand miles (some have gone much sooner) and are unrepairable because no spare parts are available. So dividing life time miles by pounds to manufacture is a more accurate measure of manufacturing load than a straight up comparison. Cecil’s analogy is like saying my scooter is full on one gallon of gas but it takes 15 gallons to fill my car, therefore the scooter is more efficient…
In advance, yes, some scooters go further but I’ve yet to hear of one that can go a million miles like some Volvo.