I see a lot of variance on people's amp recommendations for products. It seems to me like a clean 1W into 32Ω is enough to drive the majority of headphones to 120db, which is extraordinarily loud to the point of being unlistenable. Tons of middle-tier desktop amps can handle going over 5W per channel at the same impedance and some even go over 10W. Are these wattages actually useful for anything? What wattage would set you up for any headphone, regardless of budget?
Oh yes, I'm aware of the exponential nature of power growth. I gave 120db as an example of the extreme upper limit of loudness. Even the Susvara needs only 1.6W to reach 115db, which is still extraordinarily loud and gives you adequate headroom for listening at reasonable levels like <90dB. So why do amps that provide 5W or more need to exist?