You also have to look at it like this. In Cosby's case, he wasn't on top of the Comedy pile anymore and many victims also weren't in the same industry. Weinstein, who was a big name, but has not really a "fanbase" to speak of, who would climb walls for him, since he's *just* a behind the scenes guy... Vince though, especially during the first #MeToo wave, was still pretty much THE "head of the table" of a whole industry, with loads of "fans" who would immediately try to destroy anyone who'd come forward with accusations.
None of these #MeToo like cases are the same and in each case there are different reasons for why victims might not come forward (or haven't come forward immediately.)