Why did Instagram stop showing saved posts in the order they were added?

A few years ago, Instagram revamped the algorithm for displaying saved posts to show you what you're most likely to want to find first - it was supposed to help you navigate large collections. But that meant losing the chronological order, and now the sorting there works by relevance, how closely posts align with your interests, and activity, rather than by when you saved them.

Meta's algorithm for saved posts takes into account not just when you added them, but your behavior - which saved posts you view more often, how long you spend on them, whether you rewatch them. Basically, the app re-ranks your collection in real time, so an old post can float back to the top if you keep coming back to it, while a recently added post can drop down if you never click on it.