Facebook's Libra project didn't come from nowhere. The social network has a long history of experimenting with digital payments, and launched a separate (and ill-fated) digital currency a decade ago.
The market has changed a lot in the intervening years, but Facebook never gave up on its plans to launch a currency. It's clear that Facebook itself has changed too, and controls a lot more data and expertise than it did in its first years as a payments company.