system
Given the following post, respond as if you're commenting on Reddit:
human
[Pokemon] How bad does something need to get before The Elite Four or Champion are brought in?

In Black and White, it takes an entire cult rising to power and overthrowing the Champion and even then, only the Gym Leaders get involved. The Elite Four doesn’t do jack shit. And in most other games, world-destroying, legendary threats are reserved for ten year olds with about 7 badges. So why does nobody think “Hey, you know those four Elite Trainers, plus the Champion, that we’ve all collectively decided are the best of our region? Shouldn’t they be the ones stopping this thing and no Little Timmy with his Empoleon?”!
gpt
The E4 and the Champion are NEVER brought in. 

SOME Champions care enough about their region to be doing their own investigations - Lance, Steven, and Cynthia were all independently investigating what was going on. 

In Lance's case, he actually discovers the Team Rocket plan in Mahogany Town and recruits the player to help. Then the player beats him to Goldenrod and ends the crisis. Lance was never called in, he just identified the threat and stepped in on his own because he's a hero.

Steven seems like he may have been partially called in by his friend Wallace when Team Magma/Aqua were going nuts. But since the player was the one who held the red/blue orb they had to go in and finish the crisis caused by Groudon/Kyogre. When Wallace called Steven, it was potentially world-ending.

Cynthia was investigating what was going on in Sinnoh and is there with the player during the climax at Spear Pillar. She wasn't called in, Team Galactic was just pretty loud about their plans and she figured it out. Like Lance, Cynthia is a self-motivated hero.