Do you keep printed/ hand written backups of important credentials/ keys and if one chooses not to do so, what is the risk that this contributes to a complete data loss after massive solar flare?

Solar eruptions could [screw up the digital world](https://science.nasa.gov/science-news/science-at-nasa/2014/23jul_superstorm/)

In case of such an extreme event, will my personal neglect on a non-digital backup contribute to my data loss? Or can I expect that all major data center servers will experience irreparable damage anyway so my inability to sign in is the smallest of all problems?

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