I agree with a less extreme mfm. Efforts would be much better spent teaching kids how to defend themselves against bullies than preventing bullying, because that ain’t gonna happen so you might as well teach people to not be a victim. Would it be great if we could stop bullying? Obvi. But we can’t.
Another (albeit complimentary rather than exclusive) answer is to hold the bully accountable for their actions as well, though how effective this is in elementary/grade school is debatable. It’s more of a way to deal with adults, or at least the examples I can think of are.
It isn’t effective with kids. A lot of bullies get suspended or sent to detention if they’re caught by a competent administrator, but if they don’t have attentive parents to actually help them understand why it’s wrong then the punishment alone likely won’t mean anything. Most bullies that I remember were constantly in and out of the principal’s office and it didn’t change their thuggery one bit.