Does leg and arm hair have a function?

I don't believe that these hairs are important or have a function since we could completely rid ourselves of them by waxing them off, and we would be just as functional as someone with hairs on their arms and legs.

Leg and arm hair has a function - it helps keep us warm. However, the advantage is small when you consider that we have clothing and we are able to heat our environment. In our evolutionary past clothing and heat have not always been so readily available, so we still maintain some hair for good functional reasons. Hair also offers some protection against the sun and against minor abrasions.

Body hair is also a sexually dimorphic characteristic, providing a signal about maturity and virility in males.

Quite a lot of our features could be removed and we would still be able to function with little or no impairment of our functionality - in our modern state. Many of our features become less important due to the availability of technology and relative ease of living.