It's genuinely horrifying to me that people appear to be upvoting the creation of a subhuman caste and delegating responsibility to them. Please think this through a bit more carefully, it's an interesting thought experiment but a terrible idea.
Consider also that not being able to lie is absolutely not the same thing as being trustworthy. If we've learned anything the last two years, it's that people can deeply believe some shocking things.
Could these public servants be subject to being misled? They can tell the truth but they aren't all knowing, they won't necessarily know when they've been lied to.
Could these public servants be become a tool for a more powerful political entity? Perhaps truth is more subjective than we hoped, or perhaps they have been conditioned with a failsafe - to keep them from speaking certain truths.
Could these public servants decide they don't like the life they've been given? They are humans, not mere tools.
> "And yes, you could be trusted to not lie. To eschew deceit."
Leaving aside that being unable to lie has nothing to do with knowing the truth, that poor wretch would be the most unelectable creature in existence. The voters do not want to hear that "we don't know what the right answer yet", "this solution is the right path in the long run but will cause poverty and suffering today", and other unpalatable truths that are largely unavoidable as part of governing a population.
Consider also that not being able to lie is absolutely not the same thing as being trustworthy. If we've learned anything the last two years, it's that people can deeply believe some shocking things.