As Seth Godin says in his book of the same title, We're all Weird.
He means in a good way. We each have our own unique slant on the world that is weird in the sense that no one sees things exactly as we see them.
And that make us 'weird' in each other's eyes.
My wife, Shelly was at an event for our daughters recently and was talking to the father of one of the other (older) kids. He was 12.
The father was concerned that his son, whose favorite activity involved make believe sword play, would still be doing this in the basement when he turned 34.
Children begin role playing against made up, 'weird', non adult challenges at a very young age, and there is a lot more going on there than meets the eye.
Especially if you attempt to literally translate their game into real life 'work'.
What they're doing is honing their heroism skills. They are investigating good and evil, rehearsing their response, and exploring what matters deeply to them.
Left to their own devices, the complexity and 'relevance' of this activity will naturally escalate and take on greater and greater 'real world' application.
The problem isn't kids not wanting to grow up, it's parents not challenging their children and supporting their journey of transitioning their heroic curiosity into adult purpose and contribution.
The time to worry is when they've given up and turned to looking to be told what to do without questioning it.