As a registered old fart I think I am qualified to say a few words. It may be that it is different in different countries so can only talk from my own point of view.
I was always told by my parents to say please and thank you and still do today. Being polite costs nothing. Even if you are complaining it never hurts to start polite and then ramp up the anger if required. For example had an iPhone that was knacked and just days from the warranty ending. Expected to have to pay for the battery to be replaced. Went in asking for it to be repaired and battery replaced. Ended up with a brand new phone. Also similar with an iPad, battery knacked and out of guarantee but they honoured a recall that I didn't know about and got a new iPad.
Same as on here. How many ban appeals are like "Unban me, now. Didn't do wrong'? Most. it is quite refreshing when we get one that is more honest.
I usually hold a door open for someone if they are just behind me. Very few do it for me but I still do it. More often the person(s) will walk through as though it is your job and they don't even grunt a thanks. That is people of all ages not just the yoof of today (which is most people for me now).
Our neighbour is technically illiterate. So I often get called to do simple stuff like instal a printer or fix their borked PC. They need help then and it has sometimes taken hours to do. Don't expect anything in return, just a thanks, but have received help from them with stuff. It may not completely balance in terms of money but that doesn't matter.
Was just reversing out of the drive on the way to catch a ferry across to Amsterdam. Loud crunch noise. Not good. Went to our usual independent garage to see if they could help. Been going there for 20 years. Spring had broken. Despite being busy they managed to get a replacement and fit it. We were able to rebook for the next day and go. I hoped they would help but if they couldn't then they couldn't. Being polite and hopeful and always respectful to them through the years possibly helped.
I don't think it is an age thing it is more like an entitlement thing. Maybe it is TV, Facebook, media in general that is influencing people into thinking that businesses HAVE to do what they want for as little or free as possible. My mum was horrified that a plumber would spend two hours (1 of which was travel) to fix a simple problem and charge £100. Try and explain to her that £50 an hour is a reasonable living hourly rate for a qualified tradesman is like poking you eye with a sharp stick. "But it was a simple fix".
Was out shopping a few weeks back and a woman who had difficulty walking stopped and was leaning against a wall. I was waiting in the car and was going to get out and see if she was OK when a kid stopped and asked if she was OK or needed any help. She said she was Ok and was just waiting for her daughter. In aboit five minutes there was about 5 other people asking if she was OK. Eventually her daughter arrived and she explained she nearly had to move because she was getting fed up with kind people of all ages asking if she was OK!
Being polite and pleasant costs nothing but is worth a lot.
