Even if you got expensive treatment with the EHIC, it doesn't cover thins like repatriation, accommodation for extended stays if you can't travel home, accommodation for any family members staying with you, costs for rescheduling flights, etc, etc. Travelling without adequate insurance is definitely foolhardy.
I have diabetes, high blood pressure if not controlled with medication, extensive nerve and joint problems, etc, etc. My bank will cover any of that as long as I haven't had to have emergency treatment in the past 12 months. My Mum has similar problems and she always used the Post Office for insurance as they would cover everything but if you had a claim, you would have to pay a much larger excess. That seemed a very reasonable way of doing things.
On Brexit, it seems that without a deal, the French will lose out on the fishing so it is in their interests to compromise. With the level playing field, I don't understand how anyone would want to sign up to something which one side could change without a buy your leave. Even when you buy a house, car, etc, you wouldn't do this. However, I should have thought it would be fairly simple to come up with an agreement where we keep the terms we have but any new ones that we don't wish to adhere to would just mean we weren't able to export the goods which it affected. As we usually state subsidise less, normally have better conditions than other countries, it is unlikely to be a huge problem but will protect both sides from imbalancing the level playing field. Historically, we did have the power of veto in certain areas, this would be similar. As a leaver, I feel that would give this country a choice but we wouldn't expect the EU to compromise future trade on their terms.
Regulation is a little bit more difficult but I am sure there must be somebody a little more creative in thought than I to find a solution.
We are all pretty much graduates or post graduates in our family where we voted to leave. The main ones who voted Remain couldn't have debated the Pros or Cons out of a paper bag. That said, I also have members of my family who haven't a qualification because as youngsters they weren't interested in academia but are far more knowledgeable about the ins and outs of economics, the EU, etc. Qualifications are achievable for those who can perform on the day but the statistics don't take into account those are intelligent and informed but suffer from exam anxiety or brain fog when stressed.
