Once you reach the age where serious health problems can be expected (80+ ?) then any insurance company is going to jack your premiums so high you will no longer be able to afford them.
You have now paid a great deal of money to them and have nothing to show for it except maybe peace of mind during the years you did not need them.
I will "self insure" by starting off with 1M Baht once I move to Thailand at 67 in 2 years and add 100,000 each year to that.
By the time I reach 80 there should be enough money in the pot to cover almost any illness.
If I die peacefully in my sleep one night then there will be money for my son and wife.
The best insurance (just as in sailing) is to keep the boat off the rocks - live a healthy life with exercise and a good diet.