Girl, no. I'm 39, I wear leather (faux) all the time. I rock band tees, skinny jeans, vans. Even the odd mini skirt. Brightly coloured hair.I'm 33 and I'd feel a bit too old to be wearing a leather jacket though that may just be my own paranoia
Some clothes are timeless and a decent jacket is deffo one of those things. it's how you feel in them (and a good fit obvs). And confidence that's the key and if it's your vibe you should 100% wear it.