A building surveyor certifies compliance with the code. They do not check quality — and understanding that gap is worth money.
A building surveyor (called a certifier in some states) issues the building permit and carries out the mandatory inspections at prescribed stages. They can be employed by council or operate privately. Either way, their role is to certify compliance with the National Construction Code — not to check quality, finish, or whether you are getting value for money.
They do not check that your tiles are level, your paint finish is acceptable, your doors close properly or your joinery matches the drawings. A frame can pass inspection and still be a frame you would not accept. Compliance and quality are different standards.
Where the builder appoints the surveyor, there is a commercial relationship between them. That does not make the surveyor dishonest, but it does mean their appointment is not independent of the builder. Where you are able to appoint the surveyor yourself, do so.
An independent building inspector working for you — at frame, lock-up and pre-handover — checks the things the surveyor does not. On a new build it is one of the highest-value few thousand dollars you can spend.