>Competition. If I ask my OS-level AI assistant to find a social media reel about a elephant dancing, the social media app that exposes a set of APIs for an AI agent might get used more.

This is the exact opposite of what will happen (and in fact what has happened). Reddit is suing Perplexity right now for scraping.

Meta will not serve content to some other app for free - for what benefit? They will not see advertising data.