It's not great for the environment, but the average Home Depot probably stocks more plywood than the skate industry produces in a year. Wheels break down into microplastics, but I've got news for you about car tires, stretch pants, and grocery bags.
In a perfect world, we'd probably have to curb skateboarding, but for so long as we continue to chop up forests to build ever expanding suburbs, blow the tops off of mountains to extract coal, spew gas in various forms into the environment, and open-pit mine lithium so wealthy liberals can feel good about their automobile purchases, I don't see how anyone could too harshly judge skateboarding for its environmental impact