For users like me, where I never went ahead and unfollowed people I wasn’t interested in following, it’s a very long and annoying task to go through and unfollow a lot of people.
As of right now, there is no way to rapidly unfollow all the people you currently follow. The process of manually having to click on each user’s options menu, then press unfollow, wait for it to update, and then repeat with the next user can just be painfully slow, especially for people with people they follow.
Being able to unfollow all users you currently follow would be a nice addition and probably a quick one. I’ve seen some extensions attempt this however they have never actually worked, or they have and are now outdated and broken.