I've been reading on hull materials from some marine surveyor who is really upset about how poor the cored hull construction methods are.

The author touts that foam doesn't stick to the epoxy (no matter what method is used), they don't resist impact well, bad with heat/water/UV, etc.

The balsa cores are the only "marginal" cores in the author's opinion, and they absorb water & rot (which leads to failure, but not 'catastrophic' failure)

In addition, he points out, the labor costs are higher because of the skill needed for core bonding, infusion, etc.

For any high stress application, the surveyor points to solid core construction (which undoubtedly must be heavy)

Are cored hulls primarily employed for weight savings only? What other advantages do they offer?