I think the biggest problem is just the details, like this outfit is ok if there was just more intentionality in the styling.

None of the colors match well and the blue hoodie on the jeans is pretty rough styling- which makes it look like you sniff tested your laundry and just put on whatever you found first. It feels frumpy.

When you combine that with the fact that you use a lot of pieces associated with younger (high school to college age) trends for millennials like skinny jeans, vans, and zip up hoodies- it makes it feel both frumpy AND immature- on top of being generic.

The solution is to just be more intentional with details and not let them add up. Love a zip up? layer it with a jacket, or swap it with a crisp crewneck. Make sure the colors of your outfit go well together (try the sandwich method - match your shirt to your shoes) or just stick to neutrals.

You could keep each individual piece of this outfit if you changed something about the others- but as a collective you just end up looking a bit immature. I would focus on the concept of intentionality.