You are absolutely right. The kind of under reporting we have is phenomenal. Let me tell you one of my own personal experiences. In last budget government brought a provision to integrate our retail POS systems with FBR to share live sales data with FBR of each POS machine. The penalty of not integrating was 50% higher output sales tax. but to surprise me, one of the major player of the industry (who also happens to be a religious brand of the industry) refused to integrate. So unless he was slashing half of its official sales, there is no way he could have opt for not integrating with FBR. Here we are talking about formal corporate sector. Now imagine how much embezzlement opportunities are there who are dealing with informal sector of farmers.
By the way I am still ACA, but soon to become FCA within few months.