Why do the uniforms cheerleaders wear always reflect a stylized version of the fashions of about 20 years back?

Examples: Mostly footwear. When I was a kid in the late 70s early 80s and my dad took me to HS football games, the cheerleaders wore saddle shoes and bobby socks. In the late 80s/early 90s, they wore tube socks and vintage running shoes. Now, I just attended my HS reunion/homecoming, and they were dressed like late 80s/early 90s w/ socks the size of legwarmers, and reebok freestyles like I wore back in the day. I just noticed it.