I could be wrong, but I don't think many citizens would vote for a policy that would give up so much of their privacy, autonomy, and civil rights for the hope that central banks and government officials will make the right economic decisions next time given the data a digital currency provides.
The central bank doesn't have a crystal ball to know with certainty where inflation will go. Much of that depends on historical events outside the US that are by definition unknowable -- how will food and energy prices be affected by war in Ukraine, for example?
But central banks are able to plan and then adapt appropriately as circumstances change. And citizens have long voted for effective central bank policy -- economic fears about inflation and recession are reliably the #1 popular concern. If a digital currency can help this, most voters will be very happy with it. After all, for people (like myself) who already make 99% of their purchases with credit cards, they're not giving up much.
That government officials are fallible and incompetent is (in my opinion) the weaker argument. Even if they were extremely competent and had a crystal ball that predicted the future (they don't), nobody should trust the intentions or the goals of government agencies with such ubiquitous and unchecked power.
> there's no alternative that does them better
State-run EBT cards exist and seem to be working OK.
Federalizing more things reduces people's ability to usefully vote with their feet by moving to a different State when people don't agree with State government policies.
> more stable economy (lower inflation, higher employment)
Speculative and seems unlikely. Do you have examples where a CBDC helps pay for projects better than the existing payment rails?
There is no good reason for the government to have complete control over all of your finances and purchasing decisions on a granular level (if you value human freedom, autonomy and dignity at all).
The idea is that the benefits to the user are a more stable economy (lower inflation, higher employment), a more effective safety net (politicians more likely to approve payments that can't be spent on gambling), and greater peace (targeted sanctions as an alternative to war).
Whether any/all of these will work effectively is debatable of course, but there are legitimately good reasons to think they would. And no, there's no alternative that does them better, and crypto certainly doesn't. Again, the individual merits can be argued, but the idea that it is "all bad no good" is simply not the case here.