There actually are age cues in cargo shorts. It’s just that they’re subtle. Younger shorts are baggier and longer, with pouchier pockets. Older is a little more fitted and shorter — shorter as in right at the knee versus below it — with flatter pockets. The other cue is the shoe. Young guys wear flip flops with no strap around the ankle. For older guys its TEVA type sandles with an upper strap. You also see loafers with no socks but you have to careful with those or you’ll look goofy.
I like cargo shorts the same way that I like jeans. They’re easy and you can wear anything with them. They look good with a t-shirt, a polo shirt, an untucked button down long sleeve shirt, even a sweater.