You're not supposed to apply the Gini coefficient to a single asset. It's for an entire society.
Now, governance concentration, that's a useful metric for a cryptocurrency.
Now, governance concentration, that's a useful metric for a cryptocurrency.
A Gini coefficient is only useful if you treat it as a currency of a sovereign state, but it has basically no attributes of a good currency - and certainly doesn't have a state. It's not broadly accepted anywhere, it's not the unit of account for anything and nothing is priced in it. So yes, to your point, a Gini coefficient with that in mind makes no sense.
However because it says "currency" on the sticker, someone's gonna run the numbers as though it is one.
So unless you're measuring the world as a whole, you're measuring communities that have porous relationships with the outside world to some degree or other. But of course, cryptocurrencies are still much more porous than countries are.