I think the Law should reflect the society it serves. In certain contexts, DJ is outdated considering technology we have today, surely? As Munque-Chique points out.
But DJ was introduced to protect those who stood trial from the interests of agencies other than the Law. IE; if a judge returned a not guilty verdict, the courts could not be ordered by any government or head of state to re-try a defendant, just because the verdict did not suit them. Cos of course one risk would be that if a court said 'not enough evidence to convict', then such 'evidence' might then materialise (IE possibly be fabricated) which would help to convict someone who's already stood trial and bin acquitted. Or something like that anyway.
And it was about protecting the finality and absoluteness of the decision of the court. Important, and should not be dismissed lightly.
But I'm not sure if amending that Law has ensured our slide into Barbarism though, despite the cries of the conservatives.
Trouble with the Reasonable Doubt thing is that advances in technology have actually produced evidence which provides that reasonable doubt of a person's innocence.
It's a tricky one for sure.