Will Libra be able to replace Bitcoin? I believe it won't. So, I don't think we should ask the question in OP, because both Facebook and its coins, Libra are worse than bitcointalk.org, and Bitcoin, respectively. Facebook platform also does not have good systems to control their quality of their community posts. Actually, they have reports but such things are not enough for huge platform like Facebook. Reporters should have rewards from their good reports.
I believe Yes! This coin will be a game changer. As it is backed up a few big companies like PP, Master card and Coinbase etc.
And that exactly why we should stay away from it; we are talking about actual (credit) PRIVATE companies creating their own money.
Fiat money does at least come from democratically elected governments (public institutions) so even if it's not perfect, it can be controlled, and is meant to be "for the people".
Private companies are there to make money. Users don't matter. So this is a whole new level of economic liberalism (which is kind of horrible to see).
Also, more than 2.2 Billion people who are using Social media will be using it,
Just because many people use it, it does not mean it's good; take a look at drugs
It surely going to take down bitcoin.
I sincerely hope it won't and can't; and it will make real crypto even stronger