User blog comment:KaiserLos24/Skins- Symbolism or Just For Show?/@comment-4796551-20131231112543

That depends, most online games, the character's initial appearance cannot be personalized. By buying skins, most players can actually do some 'makeover' or whatever as they see fits.

In League of Legends, since the Champions' equipments' appearance cannot change regardless of the items possessed or the modes, situations their on, many players might be bored fairly easy with the same thing all the time.

So yeah, they're mainly(maybe solely) for looks only. Most of the programmers may not improve their graphics, instead, they add another appearance to their template.