Bullying is what happens when an individual with power exercises that power against people who don't fit in. By threatening to expose or harm or degrade the outlier, the bully reinforces the status quo in a way that increases his power. [Physical bullying is a different phenomenon... I'm mostly writing here about emotional bullying.]
"I will punish you because you don't fit in, and I will continue to punish you until you do."
Bullying persists when bureaucracies and hierarchies permit it to continue. It's easier to keep order in an environment where bullying can thrive (and vice versa), because the very things that permit a few to control the rest also permit bullies to do their work. The bully uses the organization's desire for conformity to his own ends.
"It gets better" has never really sat right with me. Maybe that's because the first "It gets better" video I watched featured David Spade, a guy whose career has been built on bagging on people. Or perhaps because the advice seems akin to telling a victim of violence to close their eyes and go to a happy place until it's all over. This is life, not a dental extraction. You should never have to endure pain to get to some imagined happy future.
The world is bigger than your bullies. You can find a place where you fit in, but you will have to be brave enough to look. Sometimes the bully in your life is connected to you in such a way that to cut him out of your life means turning your back on other friends and on what you have built together. At first it seems scary. You're suddenly unmoored, adrift.
But soon the calm descends. The yelling stops. Other doors open, and you are finally able to live your life on your own terms. I suppose, yes, it does get better. But only after you decide to do what it takes to make things better and do it.
You belong somewhere. A whole new life is waiting for you to find it.