It definitely helps to not have a family, and not to get sick, but if the finances work out after considering everything a generic fear of medical expenses shouldn't necessarily keep someone from pursuing an early "retirement". Home expenses are the more important consideration I think unless you've already got some medical stuff going on. I kind of did things in the wrong order and quit my job last year before finding a place to move to, and still haven't really settled on a new location, so I'm continuing to rent in high cost Bellevue WA. With no job, if I want to buy a home (that's absurdly overpriced even in places like Wyoming relative to 2019/most of 2020) somewhere and not pay in cash I'll need to do an asset depletion loan, whose typical 70% of assets calculation puts me at about a third of the more traditional 28% monthly income rule for qualification purposes.
My personal health insurance is a crappy plan that's $250/mo (it's going up to $280 for next year) -- I don't plan on actually using it and I have an HSA fund from my last job that will cover 1-2 years of hitting the out-of-pocket max if something does happen. Depending on the something, and its chronic nature, that may force me to change my situation, but top of the list of likely doable changes is to just go back to work (either to afford a better plan that'll cover something I need or get with the group plan the company has). If being "retired" young doesn't work out so well in the first few years, it's not that rough to become un-retired, compared to being in your 60s or 70s, and hopefully at least you had a fun break.