In some circumstances this desire for privacy is entirely legitimate, but in others it has more to do with tax evasion and illegal activities. Perhaps a more important source of ongoing demand is the fact that using cash does not require the internet to be up, electricity to be working and the banks’ systems to be operational.
Our  4  See Noelle Richards, “Federal Deposit Insurance Corporation Improvement Act of 1991,” Federal Reserve History (website), Federal Reserve Bank of Richmond, November 22, 2013, https://www.federalreservehistory.org/essays/fdicia. 5 Dodd-Frank Act, Pub. L. No. 111-203, 124 Stat. 1376 (2010).