A hypothetical "world government" assumes that the provinces (former sovereign nations) are transparent and have zero corruption.
Nations like El Salvador accumulating BTC reinforce this thesis. The state accumulates BTC in order to later participate in global trade in a transparent manner, with a completely open ledger.
BTC will be the world's standard currency. What worries me is that it will essentially be used by provinces of the global government and meta-capitalist mega-corporations (BlackRock and the like).