Unless you are one of the multi-millionaires on this thread, a prolonged, serious illness requiring extensive treatment is going to clean you out.
That's not necessarily true.
My wife has very serious medical issues.
She discovered one of them before we were married. That resulted in a couple of months in the hospital (with a helicopter flight from the smaller hospital to a nationally-recognized facility a few days in), about a month in Intensive Care, many, many pints of blood and a few major surgeries and several procedures. Since then (~15 years ago), there has been regular follow-up care. Most of that time, we've traveled to the big, nationally-recognized hospital despite the ~6 hour one-way drive. She had a low paying job and basically no assets, but she had great health insurance. All that care wasn't free (and the hospital bills were staggering!), but the out of pocket wasn't really that bad. It seemed like a lot at the time, and as a percentage of her income it was, but in the long-term it was only a small setback (financially, anyway).
A few years ago, she was hospitalized locally for a different major medical issue. This time, she was transferred from one hospital to another locally and then the big hospital that has coordinated her care in the past sent their jet to pick her up. That flight alone was $29,000. She ended up in the hospital for few weeks and then on FMLA for another month or so with some visiting nursing care. Different insurance this time, and we did have some out-of-pocket costs for the hospitalizations but quickly hit the maximum. Definitely nothing that a reasonable emergency fund couldn't absorb. Insurance refused to pay for the flight, but the hospital immediately negotiated it down significantly (to $9k) and we eventually got it covered on appeal.
She is only 36 years old right now and has required more medical care than many do in their lifetimes and we've always been fine, even when I was a graduate student and she was a technician making a small hourly wage. I'm not saying it was easy, but we were never worried about losing our home or going hungry.
If you end up needing them, great benefits can be way more important than a big salary!