The US also has a very poor handle on heart disease; almost 10% of men in the US have coronary heart disease. The recommended strategies aren’t working.
My father had a heart attack at 43. In response, he dropped red meat and dairy and had to have stents put in 2 years later as his condition deteriorated.
He stopped eating any foods with added oils, as well as anything fatty like nuts and avocados. He eats absolutely zero oil, just basic grains with vegetables and fruits. Ten years later and his doctor says, aside from the stents, he shows no signs of heart disease at all.
Anecdotal improvement aside, your statement about high carbs/low oil being unsustainable is false.