>>> cos no virus could sweep the whole world like this has
Viruses tend to 'sweep the world' more easily than they did in the past, simply because we've got far more people travelling across the globe nowadays than we had in historical times.
However the Plague of Justinian in 541 killed nearly half the population of Europe. The plague that affected Mexico in 1545 almost wiped out the nation, killing 80% of that country's population. The outbreak of Bubonic Plague of 1855 killed over 12 million people across many countries. Estimates for the worldwide death toll of Spanish flu at the end of the First World War vary wildly but around half of the world's population were infected, with perhaps 50 million deaths.
Scientists have known for ages that the world was long overdue for another major pandemic but Covid-19 probably isn't 'the big one' that they know will hit us eventually. i.e. it's very 'small scale' a these things go and we'll almost certainly eventually see something far, far worse.
So why on earth would you assume that it's in any way 'out of the ordinary'?