Having visited your country very recently, there are a good many cultural differences - some subtle, some blatant. It really depends on your own expectations.
If you grew up in the location where you live, then you suggest that you notice a change in behaviour ? ....or is it that you seek the same chivalry you have seen from movies or TV ?

It is probably true of the West, that the pace of life has become faster, that people have become more self-interested in their quest for greatness (!) and that equality has alarmed and confused some men. It is a shame that society has changed in this particular regard, perhaps, but efficiency and a change in priorities all point to the "race to the finishing line" mentality, where humans feel disregard for other humans.
I think also, that the lack of manners you speak of cannot only be applied to men, but also to women. In general, both genders have become more arrogant, less respectful of authority and consider themselves before others.
Sadly, sometimes, many see compassion as a demonstration of weakness; being a "gentleman" does not make a man "James Bond 007" but someone who seeks approval from others !!

You have raised a fair point, but as to how to reverse the changes...........I don't know ! 😕