Except that they do. All the time.
Because governments are not evil machines that only want to steal your money. That's just a Dunning-Kreuger / nutjob interpretation of reality that is often repeated by a certain kind of broken individual.
Governments are not evil machines. They're machines staffed by people and people do what people often do: follow the laws blindly because "it's their duty", exploit the existing laws to their advantage "because it's legal", and craft new laws to monkey-patch the flaws in older laws "because it's their job." When two opposing groups of people disagree with each other, they resort to theatrics and name-calling and the machine kind of idles in its current state. The machinery isn't evil and the people aren't evil. This is just how the machine works. If the people operating the machine decide it needs more of a resource, they'll try to get it by any any available means to keep the machine running. Their job, and belief in the machine depend on it. Whether or not the machine gives the world "a better place" is a coincidental side-effect of the machine that happens often, but not always.
Adopting a crypto-currency would give this machine less control over resources because it would either have too much transparency (no black budgets or quid-pro-quos) or perfect opacity (no ability to seize funds from victims or punish criminals financially).
Elections do not change the machine except in the sense of an oil-change--to optimize its continuous operation. The machine is never replaced. And people who do not believe in the machine are always attacked by the operators with a vested interest in the machine... a certain kind of broken individual.