This is a cyclical thing. Every generation thinks their parents' generation are all out of touch, and they think their children's generation are a bunch of lazy good-for-nothing slackers.
In my experience, the human capacity for being an asshole neither increases nor diminishes with age. I was bullied as a kid, and I know full well how stupid and cruel teenagers can be. The thing is, many of them never grow out of it.
I had a 60-year-old man try to pick a fight with me after he nearly T-boned me in a parking lot after crossing through the lanes instead of going down them (apparently I didn't respect the "fact" that he always has right-of-way). In fact, our daily commutes should remind us that people of all ages often lack basic courtesy and think the whole world revolves around them.
Some of the nastiest customers I've ever had were middle-aged and old people, while oddly enough, despite teens' capacity for nastiness they tend to cause the least problems in retail in my experience. For the past 20 years, I've seen grown-ass adults old enough to have grandkids act like complete idiots and assholes in public.
I've heard nasty bigoted stuff from older generations, who passed that garbage on to many in my generation, who are now passing it on to today's kids, and it will get passed on to generations yet unborn, continuing its long, sad lineage that should have died after the Civil War but still persists with the torch-wielding racist white nationalist and neo-Confederate mobs of today.
Point being, younger generations might have grown up under different circumstances and have different trends in fashion and music and spending habits, which might chap the asses of older folks, but one thing that never changes in human nature and the capacity of people to be idiots and assholes regardless of how young or old they are.
I will say one thing, though: Boomers and Generation X had the best music.