Yes we have the option to add steemians to our follow list and we get to see their post / articles in our feed but as our accounts grow and we meet new people on Steemit our list of Steemians we like to follow does the same. Which causes our feeds to get flooded and content we may want to see get lost. Once we log in our Steemit page will look like the below.
While you may have hundreds / thousands you want to follow for different reasons there are accounts you visit more frequently then others. A favorites option will allow you to have two list of followers. The standard Follow list and then a list of favorites.