The issue is that in most countries there is no separate health care system. There is an integrated social security system, including pensions, etc. The problem is that there is a minimum charge that you have to pay irrespective of your actual income.
This "standing charge" varies a lot. It's negligible in the UK ($15 per month) and (I believe) in Ireland. But it's awfully high in most of continental europe ($300 per month). That increases the burn rate for self funded startups by about a third.
The reason why it's so high in some countries is that you don't get to choose what kind of risks you want covered. The assumption is that you pay for the older generation so that the next generation pays for you.
It's one size fits all, decoupled from individual choices. You must pay into the retirement system even if you decide (as I have) that you are never going to stop working unless you're unable to (which should be covered by a basic disability insurance which is much cheaper)
As a result, many people (including myself at this moment) have no health coverage at all. Either because they cannot afford it or because the rules are so complicated, inconsistent and inflexible that people with unusual CVs slip through the net.