Supply of interesting and entertaining content isn't sufficient yet.

Doesn’t better content come with more users? Is this a check and egg problem

In my experience, not always. The average user does not always contribute meaningfully nor do they always have a honed compass for "better content". Most of the time, it is the inverse. Dopamine drive dictates lazy content usually wins. And FC's audience is distinctly different to those of X, Reddit, Instagram etc.

Why is everybody the goal? Have you seen what the average person does and posts on social media? It's not beneficial nor is it feasible to onboard everybody to FC. Online communities are about catering to niches.