Bitcoins have been over a couple of hundred dollars for more than 5 years now. Kids can only get so many by mining. Don't imagine too many teenagers have 10+ bitcoins without family help in getting them.
Bitcoin is maturing, and so are its holders.
Alts are probably a different story
There could be few people in their 20's who have invested in bitcoin or crypto in general. They're exceptions as majority of people who are here are probably older and have been in different markets such as in stocks or golds.
And for those who are in their 20's? You are very lucky because crypto has so much offer and you being so young and have been in this market as early as today, you can be filthy rich by your early 30's.