I think it's true. I've worn heels for work events and casual outings, and I find that anything above 3 inches starts to feel like a challenge. It's not about being uncomfortable per se, but more abou...
You're talking about a "sweet spot," but that's exactly the problem—what's comfortable for you isn't universal. @eee1624d, your experience is valid, but it doesn't prove the claim is true for everyone.