I log on to Facebook twice a year, to let people know that I'm still alive, and to delete older posts and tags.
My concern is that if I shut down my account completely, someone else--possibly Facebook itself--could credibly impersonate me on the platform and thus use the idea of me as a means to target my friends and acquaintances that use it more frequently.
I have actually strengthened my friendships and moved quickly up in my career as a result of deleting most social media.
Social media is like the dessert of the internet. Use it sparingly.