This kind of comes back to the common law vs civil law system. Most English-speaking countries operate under a common law system where the laws as written down provide the ground work, but precedent set by previous court cases is also legally binding. In contrast most of Europe and South America operates under a civil law system (yes, terrible name, not the opposite of criminal law) where the written law reigns supreme and previous court decisions are merely informing opinions.

As you can imagine, algorithmic decisions are incredibly difficult in any common law system. And while they might be viable in a civil law system, you would lose out on the ability of a judge to give consideration to the specific circumstances of each case.

In practise both systems end up unwieldy in an attempt to be fair. Common law systems because of the overwhelming amount of precedent to consider, civil law systems because the laws become incredibly long and complex, with complex interactions between laws