That's what DarkBadge's Bottomlessness dimension measures, and it's tied for the single highest-scoring dimension in both apps' evaluations: 4.8 out of 5 for Instagram, 4.8 for Facebook.
What the score is actually describing
Both feeds operate as infinite scroll with automatic content regeneration. There's no "you're all caught up" state, no chapter marker, no natural place to stop. Posts, Reels, and algorithmic recommendations load continuously, and — critically — content is served faster than it can be consumed. Instagram's scoring rationale adds a mechanism specific to it: algorithmically generated "suggested posts" that appear after a user's actual Following feed runs out, so even a deliberately small, curated follow list can't produce a natural stopping point. The feed isn't designed to run out. It's designed to always be ahead of you.
That's a specific, buildable design decision, not an emergent side effect. A feed with a completion state is a different product than a feed without one. Both apps chose the second kind — which is why the two scores land in the same place despite being different products with different feature sets.
The lawsuit's version of the same claim
The state attorneys general's coalition trial, underway as of August 2026, alleges Meta engineered exactly this — a feed built to drive compulsive use rather than serve a stated need. The March 2026 verdict didn't stop at Instagram's business model; it identified the mechanism: infinite scrolling, specifically, as one of three named design choices the jury found Meta responsible for.
The overlap isn't coincidental convergence between two unrelated groups. Both a scoring rubric built from behavioral-design research and a jury weighing expert testimony landed on the same mechanism because it's the same mechanism — described from different vantage points, same feed.
Why bottomlessness is worth isolating
Of DarkBadge's five dimensions, Bottomlessness is the easiest to verify without an internal memo: does the product ever tell you you're done? A physical book ends. A movie ends. Neither Instagram's Feed nor Facebook's does, on purpose. That absence is the product decision, and it's the one both the jury and DarkBadge's rubric identified first — in the app the jury actually ruled on.