There are some who have no favorites at all. of other people's work or of their own. I do have favorites that are mine, because of things which happened in creating them. Sometimes it's an experiment or a challenge I've tackled, and it's simply a place to store these apart from the " profile images" and galleries, for reference,. when you have a lot of different works..
I've favored and followed various people, and from time to time I've had to delete them; because they are no longer producing new work, produce to much, have changed their focus / subject / etc. So, ... it varies... for different reasons as a storage place.