The government is bound by a constitution. Violations of your constitutional rights are remediated on an individual basis through the judicial branch. You may individually hold the entire government responsible for violating your constitutional rights. This happens regularly.
The government is also accountable to you in aggregate through the voting process. Yes you don't get to vote on each individual issue, as you're not an expert on literally everything and have other things to do, so you delegate. Less delegation happens in America than in basically every other established democracy. You don't like what your representative did, vote for someone else, or run for office.
The least fortunate are the disproportionate beneficiaries of constitutional rights. Yes it's not perfect, and direct democracy tends to lead to squelching the rights of minority groups, but that's why America has a constitution plus 3 branches of government with various checks and balances.
Your employer has literally none of the above, which is why it has no business in your healthcare. If you get fired from your job and lose access to healthcare you don't get to run for CEO, you get to fend for yourself. If you're wrongly denied cover under a socialized medical system you can sue anyone and everyone involved and also vote them out, while still having access to the private markets to fend for yourself just as you would have if you left the company you worked at.
And I'm asking you not just to show that a bunch of bad stuff has happened, but that in its totality at least one country most people would consider a democracy (a good but imperfect shortcut for this is if Freedom House rates them as such) has essentially no accountability.
I don't dispute the US is non ideal, I do dispute that as a whole the government is unaccountable. For example, what do you think would happen if Gavin Newsome (governor of California) had someone killed for disrespecting him? That's the kind of thing really unaccountable governments get away with.
So I'm asking you to not only show that bad things have happened and not been adequately punished, but that the government is fundamentally as unaccountable as a reference unaccountable government, like the U.S.S.R under Stalin or Britain under Oliver Cromwell.
Yes, that's an extreme requirement. But you made an extreme claim when you said not just that democracies are insufficiently accountable to be completely just but that they are unaccountable.
Of course many governmental officials would likely be held accountable for extreme misconduct if they weren’t able to cover up the evidence. And of course certain governments are more accountable than others.