What is the rational behind ‘sector’ tax

I QUESTION the rational of bringing the so called informal economy into formal banking and taxation system.
PNG is a subsistence based economy involving over 80 % of the entire population in an informal setting. People have survived even before the existence of the Westminster system of government.
The three tier system of government does not feed them but they do pay for goods services tax by consuming taxable wholesale and retail goods and services.
They contribute to foreign exchange earnings from smallholder export crops which the government invests back to social and infrastructure services for them to use.
They are not free riders as one is led to assume.
Take for example they pay and use PMV services which the owners register with Motor Vehicle Insurance Ltd (MVIL).
Proceeds goes to the national budget to cover sector services.
Without the informal sector, PNG towns will be more prone to civil unrest and social disharmony.
It was a total waste of taxpayers’ money to hire fake consultants who do not understand the working of an economy, where both formal and informal coexist side by side, to create a safety net for the masses who fend for themselves.

LG
Observer