They can bring their systems back up and operational for less cost (both immediate, but also payroll during the fix, lost revenue from both downtown and reputationally after they're back, and opportunity cost off the top of my head).
Your only two options and rebuild on your own at significant cost or pay the ransom. There were long, heated discussions about what to do, and several people suggested paying the ransom but we ultimate decided not to and it ended up costing more than the ransom if you factor in payroll and lost revenue.
I still think out of principle you shouldn't pay the ransom, ever. Assume whatever the ransom would cost is already gone, if you can rebuild for less than that (you probably can't) it's a win.
There may have been a time when a company would act on principle, but I think it's very rare today. You hardly even expect people to do that. It's the world we have made.
Obviously none of these make it impossible, but the goal needs to be to tip the value proposition the other way.
Our backups were the data, not code or systems (which were IaC and rebuilt as needed).
When I do remediation I usually recommend restoring only business state but installing and configuring all OSes and applications from scratch with latest freshly downloaded versions. You can't trust any executable or dll that has been laying around.
That is not the restore dream that the backup provider sold them but reinfection is common. Once the bad guy has a privileged credential it is trivial for them to investigate for other vulns to use in the reinfection phase and nobody has just one critical vuln. If a business is susceptible to ntlm relay it's also going to have unsigned smb and non encrypted ldap traffic for the same root cause -- it was the default in 2005 and never got modernized.
Oh well turns out it is not like that
This is easy. It requires you to hire a lot of human clerks, but since the customers are large businesses that means there aren't a whole lot of customers in the first place. And if you can't get enough typewriters, there's no reason the clerk work couldn't be done on computers connected to printers, with all document storage still being done on paper. If the computers get pwned, throw them out and buy new ones; it doesn't matter because the documents weren't being stored on those computers.