How many actual examples do you have of the same funds blowing up which outperformed for decades? Buffett outperformed SPY for most of his 60 year career. Do y

How many actual examples do you have of the same funds blowing up which outperformed for decades? Buffett outperformed SPY for most of his 60 year career. Do you think he doesn't know what he's doing, and it was all luck, just because Berkshire Hathaway isn't doing as well as it used to?