Really looks like that bitcoin failed as an experiment
I think that it is still working as the technical experiment that it was meant to be: a test of whether the PoW/reward/majority protocol would indeed motivate miners to mine, and prevent sabotage of a decentralized ledger.
Bitcoin was not meant to be a replacement or alternative to credit cards, a sound investment, a way to evade law enforcement, to weaken governments, to turn losers into millionaires, etc.. Others appropriated it and have been trying to redefine it as some or all of these things.
The technical experiment has worked for five years in spite of (not because of) its massive "adoption" by half a million people for those purposes. From the purely technical point of view, the only problem that has surfaced in these 6 years is the centralization of mining, due to use of specialized chips and economies of scale. That development was not expected, and may spell its technical failure.
Bitcoin may be failing only for some of the things it was never meant to be used for.
