About half of exposures have no symptoms at all, about half of the remaining ones have mild cold symptoms (fever, sore throat, dry cough), and then a further 30% of the remainder might have nasty symptoms (deep cough, walking pneumonia) that don't require hospitalization. The remaining 20% of symptomatic cases (10% of total) get pneumonia that's bad enough to require hospitalization, and half of those require ventilators and ICU beds. With good medical care and no pre-existing conditions about 90% of those patients recover, without medical care virtually all of them die.

Untreated, it's basically like playing Russian Roulette. 5 out of 6 times, nothing bad happens. 1 out of 6, you die. The disparity in outcomes is probably what makes this so insidious: a lot of folks look at the numeric outcomes for healthy people in the presence of ventilators and ICUs and reasonably think "Oh, I have a 1 in 500 chance of dying, it's no big deal". Medical professionals look at the exponential infection curve, the capacity to overwhelm health care systems, and the number of patients requiring hospitalization and think "this is the scariest disease I've ever seen".