This is what Libra is: it’s an exchange traded fund, similar to the ones in your retirement accounts, consisting of a basket of major currencies. The fact that it is using ze blockchainz may as well be irrelevant, because it is a private blockchain operated by Facebook that they can edit willy nilly. It is no more or less secure than any other decently designed database they could have used for this purpose. It is just a basket of currencies. That’s it.
The problem with this is that it does not actually solve any problems in FB’s press statement. For people living in the developed world, holding Libra instead of cash is actually a negative as the local prices denominated in dollars, euros, pounds or whatever will move relative to your Libra holdings. This is an unnecessary currency risk. The majority of your assets shouldn’t be in cash anyway.
It also does not solve anything for developing countries, because the multinational Facebook will have to follow the same anti-money laundering and know-your-customer regulations as any other bank. Sending money from U.S. to Columbia and vice versa is not expensive because J.P. Morgan can’t figure out how to change a few values in a database. This same issue will persist with Libra, unless Facebook somehow intends to skit regulations by pretending that they are not a bank or a payment processor.
This is just an ETF with branding. Not more, not less. Needless to say, if you are actually a crypto fan, this is relevant to your interests in name only.