"Decentralized" value not controlled by any state; which no central bank can influence; which, thanks to "blockchain" technology, is impossible to falsify and which offers anonymity known only to cash.
A currency whose total amount is fixed in advance, so its value growth is implanted in its DNA.
And it still values what can be obtained for free, but on merit, because bitcoins are created by your computer solving a complicated mathematical problem that "hides" one of these magic coins.