Because, the powerful men can hide things for a long time, right up until they are no longer powerful.

That's like the entire point of #MeToo. Women are very upset with how much known misbehavior was going on that was kept hush because the men involved were in positions of power, and people preferred keeping that power structure stable over literally putting people doing sex crimes to justice.

What you are seeing is that when women feel like they will be listened to when they come out with a story like this, they will.

That, and there's also the simple effect of "A rich person is suddenly getting dragged through the media, perfect time to share your own gossip if you have some"

You can't blame this on a conspiracy when such simple incentives will cause the same phenomenon, and we have ample examples of exactly that happening.