Two of these crashes wiped out more than four fifths of the price. One of them, in June 2011, took Bitcoin from $32 to a single cent. If you had been watching the chart that week, it would have looked like the end.
It wasn’t, and neither were the other six. That’s the only claim this page makes. It isn’t a promise that the next fall behaves the same way, because nobody knows that, and anyone who tells you otherwise is guessing.
What the record is genuinely useful for is scale. When a headline calls a 6% day a collapse, it helps to know what a collapse has actually looked like.
The obituaries are worth reading too: three published calls that Bitcoin was finished, with the price on the day each one ran.