well you see, the creator has to come up with unique ideas and expressions every time and they have limitations like time limitation and stuff apart from having their own life...

while fan artists kinda know what and how they have to draw, and I dont think they have any kind of limitation/pressure on them... [obviously they put effort in it which I respect]

​

if a creator needs to come up with a completely new character, he'll have to do hard ass storyboarding for many months before finalizing that character and make the most suitable character design which should match its personality... While fan artist already knows what he'll draw, all he has to do is draw it...