I have just left over 1000 Facebook groups I never asked to join! Over the years Facebook has had some dubious practices and one of those is automagically adding you to groups if you commented on a post or were invited by someone. As I try to wind down my FB activity I looked at my groups subscriptions and left over a 1000, many of which had no activity for over 2 years!
Feeling much better now, and my newsfeed is way, way better!