It is the case in much of EU also: In Germany most of the healthcare is covered by the employer. In Denmark, where I reside, you get an extra coverage with most (tech-)employments that provides access you wouldn't have otherwise.
Yes, the employers pay, but you do not lose your healthcare immediately after being fired. The state provides it for you as part of the social security net. I don't know specifically about Germany or Denmark, but I suppose it's the same across the EU.
In France you can keep the insurance you used to have from the employer who fired you, but you'll have to pay for it out of pocket. I don't know whether you'll also keep the same price or if it'll be adjusted up (since you presumably don't benefit from whatever deal the employer managed to get).
If you don't have this insurance (mutuelle), the State does provide the social security (it's provided either way, the mutuelle is on top of this).
But this is basic social security. If you're in a car crash or something, you're mostly covered. If you need work done on your teeth, you're on your own.
When I needed to spend the night in a hospital after breaking my wrist, basic social security covered the ambulance and the actual procedure of putting my arm back together, but had I not had a mutuelle, I would've been on the hook for the hospital stay.
I stayed a few times at the hospital and the price was something like 20€/day. Quite affordable, especially that the price is decreasing when the stay is longer.
It may be a bit more (would need to dig the bill but it was of that order of magnitude) and I am writing this do that a non-EU person does not get the idea that it was 1000€ a day or something.
It's the same in the UK. But the interest difference with the IS I've noticed is the effect of price anchoring: because everyone has a provider of last resort, the private providers compete on features and price. IIRC my employer payed ~100gbp for Bupa, while my current employer in the US pays ten times that for my current provider.
Also, in Germany the cost of insurance is tied to income. So I went from the bizarre situation where I went from paying ~500€ while employed to less than 200€ now that my business is not generating substantial revenue.
It is the bizarre idea of socialized healthcare, were all (publicly insured) Germans share the costs and pay according to their ability to do so, while even poor people (or founders like you) can afford to have all necessary procedures done without going bankrupt.
I don't mind socialized healthcare, but this is what taxes are for. Having an "insurance" system where the premium people pay is not related to actuarial risk is indeed bizarre.
