Why is there a statute of limitations for government officials? This shouldn't be a thing when you're entrusted with the responsibilities that you are concerning an entire country and its citizens.

The ability to defend yourself of a charge disappears over time. Evidence "rots" as weird as that sounds.

Sure, but we've decided that for some crimes (like murder) there is no statute of limitations, and we have a greater interest in prosecuting those crimes than in ensuring it's reasonable for a defendant to defend themself many years later.

I think the same should be true of our civil servants who wield so much power over the populace.

When it comes to elected officials, there could be a concern that time gives the successors an opportunity to just make up the evidence.