Well, likely, many of them didn’t. Back in the day, when there was a plague, with no preventative treatment and no (or incorrect; until the 19th century measures against respiratory disease were often actively counterproductive) public health measures, many, many people died, it burned out, then flared up again, repeat ad infinitum. Flu epidemics have been on the go for at least 8000 years, say.
Like no-one at all is claiming that if we don’t use vaccines or take precautions against covid, humanity will be wiped out.