Read Before Re-share

Content often spreads on social media without people engaging with it deeply, often as part of a performative signal about and crafting of group identity.  Platforms that wish to subvert this dynamic might gate the ability to re-share content based on some kind of speed bump to estimate whether a user has actually read the content - either as an input to a recommendation algorithm that decides the importance of the content to other users, or in the most extreme case, preventing a re-share of content before this time period has elapsed, since that time period is easy to set a reasonable confidence window on. For example, on a video this could be the duration of the video. On a multi-image social post it could be only once you are at the end. On a text post it could be scroll depth or time off site.

This kind of intervention (since it would add a huge amount of friction in an existing platform) would probably only be advisable in a new platform. In general, interventions that add friction are (a) harder to add after a platform has ossified into its norms of usage, and (b) require more user buy-in.