Even Adam Mosseri, the head of Instagram, now believes that the platform put a lopsided emphasis on videos and Reels last year — and traditional photo posts were worse off because of it. In one of the answers from his weekly Q&A with users today, he acknowledged, “I think we were overfocused on video in 2022 and pushed ranking too far and basically showed too many videos and not enough photos.” Mosseri said that Instagram has since worked behind the scenes to restore a more even balance, and internal metrics show that it’s working.
A lot of UX work is based on data. You can gather data on how people are using your products, and you can adjust them to better line up with what your customers want.
That said, I think you can get too focused on the metrics and you can take your product in bad directions.
The thing you need to have to keep this metrics-based approach to UX in check is taste, and frankly it doesn't seem that those at Instagram who have taste are having enough influence over product decisions. When so many of your users are saying "I hate this" and you just point to the data and say "no you don't, you love it," I think you need to consider whether you've let the data drive you too much.
I would reading about the paperclip problem for a nice theoretical example of how unchecked data-following can lead to…pretty bad situations.