I would like to play devil's advocate
From this article I read
Unlike the volatility seen around other cryptocurrencys in the past, we believe that Libras focus on creating a stable, low inflation currency backed by a reserve or real assets is a differentiator. Further, unlike other stablecoins, Libra will not be pegged to one currency but instead a basket of assets ranging from bank deposits to short-term government securities.
https://www.cnbc.com/2019/06/18/the-difference-between-bitcoin-and-facebooks-libra.htmlWill Libra Coin bring Down Bitcoin's dominance in the market, your thought?
This is not possible, Libra isn't much accepte yet. In USA already 9-14 percent people have idea about Libra coin. European some country doesn't support Libra coin especially French. Could be down dominance of Bitcoin, when Ethereum 2.0 will arrive and Libra coin will launch.
there was no ETA when libra will be launched a so many parties are feeling pessimistic about the launch of libra. To deal with US law maker is not easy dude. it looks like libra has a little chance to be approved by the regulators. So many parties have already argued if libra can become a threat to the fiat money.
That's why so many countries in EU have declared to ban it.