I think it's more useful to think of it in terms of a Skinner box. Loot boxes, gacha, and most other mechanics in modern games are all variants of operant conditioning, and doomscrolling is a different, but equally insidious, manifestation thereof. The way the Skinner Box gets you is by giving you little, consistent hits of pleasure, keeping you performing a rote act, and so you get conditioned to perform that act continuously, even after you no longer derive pleasure, or after the actual reward has been removed. This is precisely what doomscrolling is.