ESO has so many great motifs (more and more added each year), and so many great outfits you can create with all sorts of combinations of those motifs. It's been a while since I hit the max number on my main (10), and I've got a meaningful outfit put into each one of those slots—all of which I use regularly depending on the setting, activity I'm doing, etc.
But because of the 10 outfit limit, I'm forced to pick and choose which outfits I want in those slots. I've made really cool outfits before that I love, but I can never actually wear them because the 10 I've got are used so often that I don't want to get rid of them. So that I don't forget these outfits I make I write them down using the Notebook addon. To this day I count 7 whole outfits that I've got floating around which I'm unable to wear because of the 10 slot limit.
So I'm just putting out this public call for the outfit slots per character to be increased, at least to something like 15. I don't see why it wouldn't be possible: do saved outfits incur a large degree of processing power from the servers? But it would be amazing to be able to actually wear these wide variety of outfits I make, as I love them each very much