I wanna be a man, man-cub
And stroll right into town
And be just like the other men
I'm tired of monkeyin' around!
What I desire is man's red fire
To make my dream come true!
Being that King Louie knows of fire's existence and knows that humans are capable of making it, wouldn't it have been easier if Louie or one of his monkey lackeys just followed some humans and watched them make fire from afar instead of pursuing Mowgli? Well, it's not that simple. The ability Mowgli holds allows him to bestow clear understanding, which is why he can openly talk to each and every species in the jungle.
This is a once-in-a-lifetime opportunity, and King Louie knows it. Mowgli is the key to evolution.
Mowgli Is The Animals' Prometheus
In the legend of Prometheus, Zeus withheld fire from prehistoric man, and they were "unenlightened," because Zeus is a giant dick. All of man's Hot Pockets were uncooked, and they were fucking miserable because of it. It wasn't until Prometheus delivered fire to mankind that they became "enlightened" and began to walk upright. We're talking about evolution here.
At the climax of the first film, Mowgli reveals fire to the creatures in an effort to keep Shere Khan away.
The Jungle Book
What could go wrong?
And then everything changes. Just like mankind in the Prometheus legend, the animals gain intelligence and become "enlightened." It's like Walt Disney's version of 2001: A Space Odyssey. After the events of the first film, the animals are then able to communicate with other humans (as seen in The Jungle Book 2, where Mowgli's friend is able to communicate directly with Baloo), a fact that we have to tell you outright because The Jungle Book 2 didn't exactly blow up the box office.
The Jungle Book