I thought the purpose of a crpto currency was to decentralize the recording of transactions? Also in the case of Facebook's coin the value is backed by existing currencies. If the recording of transactions is done by a company like Facebook or a country like China, what is the purpose of blockchain versus a normal database? Where do miners fit into these coins if at all? I see the value in the removal of transaction fees, but again where does crypto come in versus just using a traditional db.
I have been trying to find answers to this but the internet is flooded with junk around these topics. Any response, resource are appreciated! I feel like this stuff is all over the news and nobody understands it.