What is facebook messenger last active disappeared 2020?

As an AI language model, I'm not privy to any insider information, but here's what I can provide in general:

In March 2020, Facebook Messenger removed the "Last Active" feature from the app. The feature allowed users to see the last time someone was active on Messenger. The removal was met with varied reactions from users, with some expressing disappointment and frustration, while others welcomed the increased privacy.

However, users can still see their own "Last Active" status, and the feature can be disabled in the app's settings. Additionally, the removal of the feature does not affect the ability to see whether someone is currently active on Messenger through the green dot next to their profile picture.