The only truly decentralized currency is gold coins but they are not practical in everyday use.
Basically every object/asset that offers a total form of decentralization is suffering from various inconveniences.
If we look at what gold is mainly being used for, then it's for long term store of value purposes. In some cases it's not always doing a proper job in that regard, but for people being interested solely in gold there is no other option.
Positive aspect of gold is that governments such a Russia are stacking up gold in massive quantities. I don't see this trend reversing in the coming 5-10 years. It will be well worth keeping an eye on gold.