Addiction has a lot of definitions one can split hairs over but I note the following

The feeds are and have been for years highly random (at least one anecdote of two people who were 'married' - relationship status - on FB yet none saw the others' posts)

If you don't go on FB they really don't like it and they spam you to death

Can Zuck meaningfully claim they're not in the business of addiction, whatever else? No. His life philosophy is "dumb fucks"

Edit: Oh, and People You May know. Now everyone can friend you and you have 2000 friends... none of whose posts you'll ever see. And the psychological baggage. Is the cute girl I like looking at my profile and that's why they're on there, or is it shamelessly pulled from geolocation data?