There is a big advantage of this feature as it allows you to share whatever you want without revealing your identity. This is more useful when the information is more sensitive to share publicly.
On the other admin and group moderators have access to see your identity and disable the feature anytime they want. This feature is limited to FB groups only.
You can learn more about this in this blog :- https://ityug247.com/how-to-post-anonymously-on-facebook/
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