Libra has raised fears about the future of blockchain mainly because it goes against everything the community wants and believes in: decentralization.
Facebook could ultimately create a massive closed-loop revenue model from ads, digital marketplace, to payments. Do consumers want to bet on the status quo of existing monoliths?
https://elixxir.io/blog/is-libra-the-future-anyone-wants It seems to me that Libra will not become a cryptocurrency, it will be something like Tether, personally I will not invest and keep this coin, but a large number of people will learn about cryptocurrency and Bitcoin thanks to this project.