Probably more than one correct answer, but many years ago a local surveyor told me that one important reason they ask for an "insurance survey" was to prove that the insured asset actually exists.Why do Underwriters then insist on a "Survey"?
Evidently there are some small % of claims for sinkings where there was no boat. Further, there's the whole condition, basic fitness for purpose, and (residual?) value for the insured asset.
So, I really do not have the answer, but am willing to toss an extra onion or carrot into the stew.....