Question about Avatars. Why does everyone hunt for them?

Hello. I've recently returned to Neopets, I originally played during 2001, haven't played since (despite my account being 5 years old, I created it, never touched it and just started recently and got hooked.)

I lurk here mostly, and always notice the Avatar acquisition post. Is there more to this than collecting these? Or do people just like collect? Do you get something for collecting them?

I haven't gotten many of them, I've been just passively getting them randomly here and there. Should I be getting as many as I can?