Bitcoin's decentralized, Libra's centralized. That's the main difference.
It is said to be decentralized. If you are reading the post of Mark Zuckerberg, you would already know that. I don't even know what is happening with Mark's brain right now but I think this will fail.
Let's get a few things clear. Decentralized in the sense that it will be handled by 100 different nodes spread around the world. BUT and it's a big BUT... It's running on a "Permissioned Closed Block Chain"... the same as the JPM coin. There is nothing decentralized about it in my humble opinion. It's less decentralized the Ripple and I don't even consider XRP a proper decentralized coin. Anyway, that's my two cents worth. It's possible the coin will do well among the masses. Probably because they won't know the difference nor will they care. All they will care about is convenience until it bites them.