Instagram added a feature which lets you sort through account and see who you interact with least frequently in case you want to unfollow them. In an effort to help to keep the feed clean and relevant. Today Instagram is launching “following categories” that divides the list into MOST SEEN IN FEED and LEAST INTERACTED WITH. that way is someone annoying or boring,or whose content you’ve proven to not be interested in you can easily remove them.
The update is rolling out now, if it doesn’t show up for you, try force closing the app and restarting. The feature may be slower coming to Android phones and IOS.