I need no convincing that performance matters, I'm a performance engineer by profession. You're kind of contradicting yourself. The numbers you use (100ms, 1s,

I need no convincing that performance matters, I'm a performance engineer by profession. You're kind of contradicting yourself. The numbers you use (100ms, 1s, 3s, etc) are well researched performance perceptions linked to our biology, in a way they are timeless guidelines. That scale of attention span places both 9s and 12s in the exact same box: you've completely lost your user's train of thought. Is 9s better than 12s? Obviously, yes. But that wasn't the point. My point was that there is such a thing as diminishing returns. If I were to follow your train of thought (performance absolutism), we should next optimize for WAP, if you're old enough to know what it is.