What replaces Facebook or Instagram time?

The source indicates that when users deactivate Facebook or Instagram, much of the time freed from these platforms is substituted with usage of other smartphone apps. Specifically, for Instagram users, the deactivation resulted in insignificant changes to total app usage, implying that the time spent on Instagram was reallocated to other apps. For Facebook, deactivation decreased overall app usage by an estimated 9 minutes per day, although around three-quarters of the reduction in Facebook usage was substituted to other apps^[1].

This suggests that rather than reducing total screen time significantly, users tend to engage with different applications during the time they would have spent on Facebook or Instagram^[1].