Suppose there are 100 copies of the block chain, and 98 become corrupted. You only need the 2 remaining nodes to verify each other and the others would just dow

Suppose there are 100 copies of the block chain, and 98 become corrupted. You only need the 2 remaining nodes to verify each other and the others would just download the block chain from them. That would bring other risks like conspiring to rewrite the history (51% attack). But that risk becomes lower the more nodes there are. With 80K+ nodes currently [1], a cosmic event strong enough to kill 99% of the network would surely qualify as "life-threatening". [1] https://luke.dashjr.org/programs/bitcoin/files/charts/historical.html https://luke.dashjr.org/programs/bitcoin/files/charts/histor...