We’ve known that pandemics were going to get more likely as international travel got faster and cheaper, and population density rose and absolute population numbers rose. These factors have been part of the horror stories that epidemiologists tell each other late at night when the lights are out:
“so it was a normal year, and airlines reduced the cost of India to USA flights by 20%,”
horrified gasps (the audience knows where this story is going)
Pandemic might have seemed improbable to you as a layperson, but the medical community has been bracing for this for decades. The less seriously you take it, the less seriously your politicians take it and the less seriously pandemic preparation gets funded.
https://youtu.be/6Af6b_wyiwI