So? OP claimed nobody was willing to do private communication on facebook/meta infrastructure. More than 2 Billion people on the planet do just that on WhatsApp, which is Meta. It doesn't matter that WhatsApp started as its own thing, it is owned by Meta and people use it all the time for very private things.
Facebook messenger is another example, hundreds of million of people use it all the time.
Facebook messenger is another example, hundreds of million of people use it all the time.