"Libra is designed to be a better payment network"
It looks the current systems work well enough. In which way it would be better? Better for Zuck who will be able to slurp all transaction data, of course, something valuable that still escapes its claws.
Backed 1:1 by currencies that can fluctuate one against the others? Looks plain BS - or a nice way to say "put your real money in our coffers, we'll give you some vouchers you can spend only at businesses that bowed to us, at a rate we decide!"