>>41469759>>41474929Black and White (and B2W2) also made Gym Leaders more significant to the story and gave them character outside of . These weren't static obstacles that live in a gym and only serve to give you a gym badge when you defeat them. They had lives outside the gym, had relationships with one another and other characters in the story. The individual themes they had for their gyms and their own themes when they were down to their last Pokemon further set each leader apart from one another. They even evolve as characters throughout the story, with some gym leaders stepping down from their role to pursue other dreams or train.
It was extremely disappointing in Gen 6 with X and Y when gym leaders went back to being nothing more than obstacles you fight for a badge. Some of them never even leave their gym. Remember pic related from X and Y? Probably not. There is nothing memorable about him or his gym.
At the very least we are getting back to gym leaders having a bit more character in recent Pokemon games since Gen 7. But they aren't as close as those in Gen 5.