I do the "same thing", but using PostgreSQL `EXPLAIN ANALYZE`. EXPLAIN ANALYZE has information about the number of rows returned, which means I know exactly which node in the query plan failed to return expected values.

don't mean to push the goalpost (didn't mention the following in the above post)

these functions can also be exposed in admin ui's making it easier for the general admin users/support users.

another very useful use case is when row level security (RLS) is enabled.

Not for function though unless you specify it as a debug flag inside the function?