> enables the separation of state from wealth
The largest beneficiaries of a currency that cannot be regulated by governments are the people those regulations currently affected by those regulations..
The average citizen in Venezuela or India generally doesn't have enough money to have to worry about financial regulations. Even if they wanted to take advantage of a blockchain currency, ss justinfrankel suggested, is will be hard for the average person in (e.g.) Venezuela to participate. If refugees had enough cash to make blockchain storage worthwhile, they wouldn't be refugees. Refugees have immediate security and survivability problems, not financial problems.
On the other hand, a global currency that cannot be regulated by any government is perfect for moving large amounts of capital to avoid taxes and the limiters, safeguards, and other regulations that try to keep modern markets from catastrophic failure. I cannot think of a more efficient way to destroy modern democracies than taking away one of the only tools governments have to affect the other place power has been concentrating: large businesses.
Incidentally, unifying money across countries that have independent economies and monetary policies creates an imbalance that can ruin the participating economies. We've already seen this happen in the eurozone[1][2].
> take control back from their oppressive leaders
That fight is political, not financial. You're talking about a Hollywood plot, not the actual daily reality[3] of people living through that kind of conflict.
> The world is already moving to digital cash
It's very important to have traditional physical cash, because it's the only way to engage in transactions that cannot be controlled or traced[4]. Moving to digital currencies is handing power power to yet more middlemen trying to extract profit and accumulate power.
> is whether we want this digital cash to be [...] traceable by the government,
Blockchains are a pubic ledger, and will always be traceable by definition.
> This is an example of a problem a centralized database cannot solve.
A decentralized database cannot solve it either, because it's a political and social problem, not a database or financial problem.
[1] https://www.youtube.com/watch?v=B6vV8_uQmxs#t=778
[2] https://www.youtube.com/watch?v=9fP6YSCpm8g
[3] https://www.youtube.com/watch?v=kmvAdRntWH8
[4] serial numbers are a problem given the power of modern technology. Actually being untraceable requires careful, regular mixing with a different parties.