Even if you have a disaster recovery plan on paper, how can you quickly get your business back up and running if you no longer have the equipment, personnel and customers available? When hurricane Katrina devastated New Orleans, how long did it take for businesses to resume operations? How many permanently went out of business, despite having a backup of all their records? It's not just the preservation of records, you have to have workers, customers, other business partners, suppliers, equipment, and the infrastructure of your area, and the areas you service functioning. That's the big picture!
@BlueSpruce - I live in the 'burbs to the west of the city of New Orleans and was intimately involved in Katrina issues as applied to the U.S. Navy Reserve - see post above for specific story.
The estimates made for New Orleans business recovery was that it would take 20 years minimum to return to "full activity" (whatever that meant). The fact is that due to infrastructure issues, it is taking longer. The COVID pandemic didn't help. What ALSO didn't help was that a LOT of folks just abandoned their homes as lost causes, too expensive to repair (even when dealing with insured properties). Between insurance companies folding and declaring bankruptcy, plus scammers who soaked up insurance payouts for essentially no work, a lot of folks in the New Orleans lower 9th ward just moved to another city. Houston caught a lot of folks, but that part of the city is STILL blighted by folks who left and never came back.
Even in my area, where we had standing water 2 ft. deep for 3 weeks, rebuilding wasn't fast. It took us 14 months to get the house back to a livable state and 12 of those months was spent looking for a contractor. While I was in Ft. Worth, my wife lived with her mother in our suburb. Her mom's house was on 3-ft. cinder-block piers and so was never flooded. Minor roof damage but otherwise livable. Wifey reported another problem that slowed everything down... building supplies. She was a frequent customer at a building and hardware national chain store. In idle conversation with one of the clerks, she learned that every day, 18 tractor-trailer rigs would drive up to the loading docks and drop off 18 full trailer's worth of stuff - but by about 6 PM that evening, 99% of what they dropped off would be sold and people left every day, disappointed that there was nothing left to sell. We were lucky because we had the ability to be patient and careful.
A lot of businesses didn't return. Some non-chain restaurants in the Gentilly area (it shows up on Google maps) never came back due to having 8 feet of water in the buildings, which represented a total loss of gas & electric appliances and other types of infrastructure. Draining that water took so long that even stainless steel fixtures didn't fare so well due to chemicals that made the water toxic and acidic. Stainless steel cafeteria furniture had holes all through it. And it was once one of the better Gentilly area sandwich/lunch shops, with a really big daytime business.
The biggest "gotcha" has been that the failure of the drainage system led to persistent flooding that weakened the ground (turned firm soil into slush), thus changing the structural stresses on the water, sewerage, and underground utilities. When pipes started floating rather than resting on solid ground, they FLEXED - which metal pipes don't like. For the first five years or more after Katrina left, it was estimated that well over half the purified water going into the water infrastructure was leaking out, leading to sinkholes and failing streets. Right now, due to a REALLY bad mayor, New Orleans is estimating a $160 million shortfall for next year's budget, including continued road and pipe repair. In the past five of six years we have seen quite a few buildings partially collapse, usually brick facades, due to "flexible" soil foundations. You might say that it should have been fixed by now, but there are only so many folks available to do the work and we are talking about a whole city. Plus it was literally BILLIONS of dollars of infrastructure damage. And, of course, the construction scammers came by to pick up their share.
Hope that gives you a good overview.