Analytical Procedures – SUBSTANTIVE Stage

Substantive analytical procedures are one of the most useful methods of gathering evidence that is often neglected by auditors. It can save time and effort and reduce audit risk significantly. There are circumstances where it might be less useful but it generally complements other testing quite well.

The primary purpose of substantive analytical procedures is to obtain evidence, along with other audit testing (tests of controls and substantive tests of details), with respect to financial statement assertions for one or more audit areas.
They are more suited to large volumes of transactions that tend to be more predictable over time because of the fact that they rely on relationships that exist between data.
Their nature allows them to often provide evidence for multiple assertions.
They might identify audit issues that may not be apparent from more detailed work.
They may identify additional control weaknesses and result in re assessment of risk.

Substantive analytical procedures directs attention to risky areas and the assurance obtained reduces the amount of assurance needed from other tests. The best approach is to carry out substantive analytical procedures before other substantive tests because the results often impact the nature and extent of detailed testing.

Inertia and Lack of knowledge on the part of auditors are likely reasons why there appears to be no practical benefits.
For further reading:
https://www.accaglobal.com/content/dam/acca/global/pdf/sa_sept10_audit.pdf