Not defending the US healthcare system, but I’ve never heard of an insurance plan without an out of pocket maximum. For example, my plan has a 2k maximum for individuals and 4K for married couples. Combined with a health savings account (allowed to be funded pre-tax from both the employer and employee), I’ve generally put $1-2k a year in that during my 20s when I rarely needed medical expenses. I still haven’t had a year where I’ve spent more than I’ve saved to the point I could cover multiple years of out of pocket maximums just from that account.

And since it’s a “savings account” I can invest the tax-free savings into the stock market with index funds. I’ve actually had a decent amount of growth in that account just from stock market gains.