You’ve something as fact, though an incorrect one: “a normal HbA1c level is between 3.0% to 7%.” This is not normal A1c range & I’d like to see one reputable source that states this from any country.
There’s sufficient research showing that the closer to normal A1c’s are, the less complications people have. No point in arguing this since the studies speak for themselves, if you’d like to research this for yourself. If studies aren’t enough, commonsense dictates that high BG as evidenced by high A1cs aren’t healthy. Over 140 causes damage & this is a fact.