Trying to take an abuser by oneself is obviously not working - unless they have overpowering evidence or sufficient money or power to take on the abused.
It's always going to be hard to prove something in a "he said - she said" (or other combinations thereof) situation. But if there were a 3rd party who could aggregate abuses against an individual or organization - then individuals would be more willing to come forward. As evidence - see what happened when the reporter from the New Yorker was able to get enough data to overwhelm Weinstein.
Too bad in the case of the gymnasts that they didn't have a 3rd party mediator that could have assimilated all of their stories together and fought back collectively sooner.
Somehow we've got to enable the single abused individual find others in similar situations so that their combined testimonies overwhelm the bully abuser.