I hear what you are saying, but I think it is tad more involved than that.
I am one year older than you and I understand what you are saying about parents buying things for their kids, but I also know that my grandparents thought my parent's generation were too soft and spoiling us. Every generation seems to think this about the next.
When I turned 15 I got my first job, bagging groceries. Any teenager that wanted a job could find one and it was not really all that hard.
It is not that way any longer. My children are 27 and 20. When my oldest was 16/17 she struggled to find a job and only got one because a friend of mine from church was the manager at at craft store. She got her 2nd job because my best friend's wife worked at the YMCA and gave her a person reference.
Fast forward 7 years and I am no longer a part of the church and do not know anyone that works for a business that would be hiring teen agers and my son struggled to find even fast food work. There was no widely available jobs like when I was that age. He got hired when a Freddy's opened a new place in our town and they over hired for the grand opening. After 6 months almost all the teens were gone and my son was working with 25-40 year olds. Then he got fired because he would not work till 1 am on school nights as he was still in high school.
My daughter is now 27 and making 6 figures, she has found her niche. My son went to lineman's school and got his CDL but cannot find work using either because he is only 20 and companies insurance will not cover a 20 year old driving something that requires a CDL plus it is only good in one state at at time till he turns 21. So he is in holding pattern for the next 10 months working shit jobs that do not pay worth a damn till he can use what he worked so hard to learn.
It is a lot more than just "culture thing", it is also an economy thing.