The course of the disease is quite variable. I was exposed at an indoor gathering where at least 4 people tested positive within 4-5 days. The person standing next to me spent 2 weeks in the hospital with COVID and has to be on oxygen for several weeks at home. I'm a good 20 years younger, but my case was mild. I assume we had similar exposure, but the other person has pre-existing auto-immune issues, is a bit overweight, and presumably doesn't take anti-virals. I'm a retired teacher, so I've been exposed to a lot of bugs in recent years, in addition to those our two sons brought home when they were small.
Our son works in an ER and sees COVID patients every working day. He says until recently they were mostly old, obese, or both. More recently he is seeing younger people who aren't terribly sick. They are scared and their doctors refer them to the ER to be sure their lungs are OK. Need for reassurance + CYA by the primary physicians = ER visit.