"Decay" in aspects of English grammar

[NikkiBarber]

The structure is changing too. The strive for juvenility demonstrates itself in various ways, one of them being addressing other people, and expecting to be addressed, as "you".

That is just strange. It sounds like my extremely feminist friend who actually gets offended if a man holds a door open for her. She will start acting like he is attempting to tie her to the kitchen sink by the strings on her apron just because someone is being courteous.
Although younger people might typically use one form of "you" it shouldn't make someone feel old because they hear themselves addressed with the more polite/less familiar form.

[birdeen's call]

That is just strange. It sounds like my extremely feminist friend who actually gets offended if a man holds a door open for her. She will start acting like he is attempting to tie her to the kitchen sink by the strings on her apron just because someone is being courteous.
Although younger people might typically use one form of "you" it shouldn't make someone feel old because they hear themselves addressed with the more polite/less familiar form.

Maybe it shouldn't but it does... It's most common among ~20-year-olds who face the shock of becoming adults (and being treated like ones). But there are some people who never want to accept this sad fact that we're all aging.

Perhaps paradoxically, it is easier for some to accept being called "sir" or "madam" by people older then them. Younger people address one another as "you" so when a young person calls me "madam", I may hear, "You're not one of us anymore." (I don't. )

[NikkiBarber]

When you mention "madam" in that context I do remember being slightly surprised when people addressed me by the Danish equivalent, but after moving to the southern part of the U.S. I have a different attitude to that word. Here it is considered rude to answer just "yes" or "no" to most people, unless you are very familiar with them, and people almost always say "yes sir" or "yes ma'am."
You would even say "yes ma'am" to a four year old girl so that she would understand that this is the polite way of answering someone. I am all for anything that makes it easier to express your respect for the person you are talking to so I like this phenomenon.
But I admit that in a place where this is not common someone might be hurt if they didn't feel that the word was appropriate to them. I guess it depends on the situation. If someone thinks of me as a lady I am pleased, but when a man calls me "lady" in a certain way it really annoys me. It depends on the speakers intention.

[MrPedantic]

The ease with which a discussion of the 2nd person singular transmutes into a discussion of cultural nuances perhaps confirms that the reason for its gradual non-use in standard English of the C17 and thereafter was also cultural (i.e. it didn't express something for which any need was felt).