I think using floppies is a great way to safeguard privacy. Even if someone finds those disks, they won't be able to read them
You're conflating two entirely different things. US nukes were not hacked, that's a massive exaggeration.
"Shaylyn Hynes, a DOE spokesperson, said that an ongoing investigation into the hack has found that the perpetrators did not get into critical defense systems."
"They found suspicious activity in networks belonging to the Federal Energy Regulatory Commission (FERC), Sandia and Los Alamos national laboratories in New Mexico and Washington, the Office of Secure Transportation at NNSA, and the Richland Field Office of the DOE."
https://www.politico.com/news/2020/12/17/nuclear-agency-hack...