Big money figuring out the value bitcoin offers them is coming. The only question is when.

As long as governments benefit more from modern slavery (which is what fiat money truly is), than from a form of money than is immune to outside control, they will not adopt BTC.
Russia or even places like Iran or Venezuela may have their problems with outside powers, but even for those countries fiat is still essential in extracting labor from their citizens.
Very true.
However, let us bear in mind that governments aren't the only ones with big money. As much as we all love to hate transnational corporations, the fact reamins: These entities have no real incentive to store all their wealth in nation-state fiat, and very soon they will have an
abundance of reasons NOT to store their wealth in nation-state fiat.