The correct answer as is often the case is “it depends”. It depends on the overall design of the amp, the speakers used with, how loud one wants to go, how big a room, how far away from the speakers, and yes even the kind of music and recording being listened to.
I think that pretty much covers it.
Not to mention each person’s personal preferences alone might lead them any which way.
In any case it’s always better to have more power than needed than less. That’s called headroom and is a real engineering concept and not just marketing. You can look it up!
Too little power means clipping occurs. Clipping is a signal processing concept that you can also look up and is good sound public enemy #1. Most tube amps and many Class D amps and a few others soft clip which at least makes some clipping listenable but it is still a defect in the reproduction of the sound and should always be viewed as a negative to be avoided.
Any discussion about power without reference to clipping is basically useless. More power can be viewed as an “insurance policy” to avoid clipping.
Case closed, right?
https://en.m.wikipedia.org/wiki/Headroom_(audio_signal_processing)
https://en.m.wikipedia.org/wiki/Clipping_(signal_processing)
