Facebook is
ordering
users to switch to a different Messenger app which demands access
to lots of
personal
information.
It's proprietary software, thus inherently
untrustworthy, so using it is an act of folly. The same is true
of Facebook's main app, and the nonfree program (in either iThings or
Android) for accessing the app store where it is released.
In Android, that program is called
Google
Play, and it has a back door that is more or less universal.
Of course, you shouldn't be used by
Facebook at all,
because it extracts personal data that nobody ought to know.