The Dark Ages Were From the Fall of Rome to the Norman Conquest (476-1066)
Ruling class histwhorians try to cover up for their bosses' degenerate rule by taking that off the table as ever having any effect on history. The Spanish Influenza, 1918-1920, killed between 50 and 100 million people. Why didn't that destroy modern civilizations?
Because the population levels in 1918 were far higher than they were in medieval times, that's why, plus modern public sanitation practices at the time shortened the run of epidemics, by responding relatively quickly to them. The influenza epidemic did indeed have an impact, but it didn't depopulate entire towns and regions. Modern civilizations are far more resilient, at least in the West.