I'm not an expert in american insurance policies (not even a novice, tbh) but if you have an ongoing condition and then lose insurance, and then get new insurance with your easy-to-get new job then would the ongoing condition be considered a pre-existing condition and hence fall into question regarding cover?
That phrase is key. Most Americans don’t have savings. Even among the professional class, savings are often nowhere near high enough to pay OOP for insurance at market rate.
I agree that it is stupid to tie health insurance to your job, but it isn't the big deal you make it out to be, so long as you have savings