Because the issue with noise is it causes disruption in your sleep cycle and possibly prevent you reaching deeper stages of sleep. White noise is fine and actually considered beneficial because it provides sufficiently consistent noise that can help mask other sounds that may be disruptive. It boils down to monkey brain still worried about animal coming to eat you but not worried about sound of rain hence millions of years of evolutionary selection on our brains to wake on sudden noises but not consistent noises.
Do you drink coffee? If so how are you going to know if your tired or not?
I see you repeating the claim that it makes sleeping more difficult, but I do think those that listen to sounds, be it ocean waves or someone talking, have the experience that it makes it easier for them to fall asleep.
Sure, there can be problems with sleep quality for numerous reasons. However, making a blanket statement that this disrupts the sleep, especially of those that have positve experience with it, is going to need some factual sources (that I do not think exists).
According to what I have read, it is fine if it is not too stimulating.
EDIT: Also, it is easy to take a break from coffee: It only requires not drinking a few cups. Either way it does not really prevent fatigue, at most delaying it.
As I said, if the noise is sufficiently consistent, then there probably wonβt be a problem with it. Content, though, implies something more than just background noise.
You missed my point about coffee entirely. The point is that if you take coffee, you donβt know that youβre tired, regardless of if itβs effective or not.
I am pretty certain our brains evolved to filter out friendly/known voices some tens of thousands of years (or more) ago. I feel tired sometimes before and after coffee, and often less so on coffee breaks because the real issue with coffee is that the caffeine can definitely disrupt sleep.
I understand you need consistency to be engaged by sounds. I hope you understand that other people have other limitations, hence, again, it is your first statement I disagree with.