[miki123211]

Or, to put it another way:

Meta makes money from ads. To make more money, they either need to capture more of their users' time and show more ads, or show better ads that users click more often.Meta is betting on AI models making it easier to do both.

Better generative AI means you can make more ads faster, which means there are more ad variants to a/b test across, which means it's easier to find an ad that users will click.

To make users stay on their platforms, Meta figures out what content will keep them there, and then shows them that content. Before gen AI, they were only able to show existing content from real users, but sometimes the "ideal" thing for you hasn't been created yet. They bet on the fact that they'll be able to use AI to create hyper-personalized content for their users that engages them better than human-made content.