Well, the thing is people who judge set contests are often not set makers, so they don't realize the work that goes into non-animated sigs. They often choose winners that did almost nothing to a picture--you know the infamous crop-sig winners. That is NOT the case with our monthly contest in this group though. The judge is a fellow set-maker, so their judging should be more "fair." this will sound arrogant but i know FOR SURE a single sig i make possess 2x (at least) more layers + manipulation than 90% of animated sigs (even the gify-clippy ones). that is saying something.
I make animated sets, and outside of AF I make gif sets. For contests and auctions, I always offer the non-animated version of anything in case the person would prefer that or don't like animated sets. I think the trick to making a nice animated sig (or gif) is to use a texture that has a grainy/sandpaper look to it to keep the colors from making the entire thing look awful. An animation for me, shouldn't take away from the image itself, or be distracting. *In case no one knows what I'm talking about with the texture, I mean like this one here that I made where I applied it. I apply the same thing to a signature, although about 80% of the time I prefer to to make normal non-animated sets.