This is how you solve bullying: remove the bully. If at work, fire them; if at school, suspend or expel them. This is effective. Anyone in a position of power to move people around can therefore solve bullying in their territory ... if they choose to do so. Most do not. You may be able to convince the authorities to act if you point out that bullies make an employer hemorrhage money. Employers may not care about their employees, but they certainly care about their cashflow.
Trying to solve the problem any other way is unlikely to work. How unlikely? The most effective solution, filing a lawsuit, has a dismal 16% success rate. Leaving also works, but is unavailable to many people, and even when available requires great sacrifice from the victim, which is not much of a success other than surviving a serious threat to health and survival.
By all means, understand bullying and bully roles and be an upstander. Suggest that the bully get therapy. Teach conflict resolution, mediation, and peacemaking skills. These are useful things for people to know. But they will not stop a bully who likes hurting people. The only way to do that is to make it clear that amusing yourself by abusing others gets you ostracized from society. Separate the bully from the victim, and impose the burden of doing so on the bully.