Deflation is more of a nightmare than a joke. It basically means the economy has significantly contracted and that wages are going to plummet across the board. This leads to a massive spike in debt defaults.
In the 19th century and in 1929 currencies were pegged to gold, so you could not just print money. All periods of economic crisis were deflationary, and the central banks did not have a lot of tools to fight that. That’s the origin of the idea that deflation is worse than inflation. This is just bogus nowadays.