I think the biggest thing today is that our kids are not into guns, knives, hunting, fishing, camping, vintage cars, or most collectibles the same way we were (Baby Boomers that is). Of our 5 kids, along with their 5 spouses, only half of them own just one gun and that's primarily for self defense. No desire to collect guns, compete with them, or use them for sport or hunting. I still know of a few gun collectors but even that number has gone down considerably over the last few years. And it's been 8 or 9 years since I went to a gun show (use to go to one every month). Likewise I don't know of anybody still collecting sports memorabilia like baseball cards and all of the card shops have long since vanished, just like the big shopping malls of the '70s and '80s.
My one son for instance has a nice paying job and recently bought a house but his two great passions in life are playing video games and traveling to other countries. He has no interest in collecting anything, drives a 9 year old car, and is somewhat reluctant to accept any of my guns. Most of the other kids prefer to travel, go on cruises, or spend their money on entertainment and going out to dinner. As far as I know none of them collect anything.
It's just that over the long haul our "free time" pursuits, like hobbies and collecting, change and the generation after ours no longer share those same interests as we did.