My wife and I self-insure a lot of risks, either by not carrying insurance at all (dental, vision), or by carrying a very high deductible (auto, homeowners).

We both have employer-provided medical, and despite a significant net worth, we would not self-insure this risk. As others have mentioned, at least get coverage to take care of the big injuries.

1. Catastrophic/long-term medical care is outrageously expensive.

2. If you can pay regular doctor visits/lab work/meds out of pocket, fine (although even that stuff can add up)

3. If you are seriously injured, you will likely also lose your earning power due to being incapacitated... so medical injury is a "double whammy"