Shark onesie at 16?!

Should I be concerned? My daughter spent most of last Sunday in a shark onesie. I'm not kidding, full shark, fins and everything, shuffling from bedroom to kitchen to sofa. She wasn't sick or upset. I noticed I felt amused and mild concerned. Didn't ask anything. But I asked myself: what exactly am I concerned about? The blanket-robe, the onesie, the wearable shark - these things are everywhere right now. Young adults going back to live with parents, gaming for eight hours, dressing in things that signal "I am not available for adult things right now." And teens doing the same, one age bracket earlier. I think most of it is fine. The world is a hard place to grow up in right now. Maybe the shark onesie on a Sunday is a pressure valve. It's not the same as refusing to grow. But I've also been wondering: at what point does the valve become the default? When does "I need a day off from being a teenager" turn into "I'd rather not be one at all"? I don't have an answer. But I think it starts with watching the pattern, not the object. Am I wrong?