Humans evolved from animals that walked on the ground, on the part of the hand/foot we would call fingers/toes. Like most animals btw (https://en.wikipedia.org/wiki/Digitigrade?wprov=sfti1).
Then the those animals transitioned into arboreal creatures, which evolved hands in order to climb & live in trees. These animals would’ve had hands & feet like monkeys.
Then those arboreal animals transitioned back into walking animals that didn’t climb as much, which turned their feet into something more like chimp/gorilla feet.
Then those animals began walking upright, which changed their feet to lose the ability to grasp since they no longer climbed as much. This is what gave humans the feet we have now.
Well radio was originally mostly about advertising, and when TV came around it was just gonna be radio but with moving pictures! So yeah, it was about spreading more advertisements around to more people.