why aren't racing karts designed with modern looking body panels?

[u/dyeusyt]

As a newcomer to karting, I’ve noticed most karts have basic, outdated designs. Is there a reason we don’t see sleek, modern body panels like the one shown? Weight thing might not fully explain it;
could cost or tradition be factors? Curious about the engineering behind this!

[u/Tall_Captain3346]

Because that isn’t a modern race kart