Why is New South Wales the only state that effectively forces customers to have a lawyer witness their attorney documents?

In New South Wales, the law society has successfully lobbied the government over a number of years to achieve this outcome.

While submissions have been made to relax the rules so that they align with all other States (which allow an array of people to be a qualified witness) if anything, the rules in New South Wales have in fact tightened over time rather than become more flexible.