"if the core container (decking, etc.) remains intact and no water gets into the cored material,
The hassle is the sealants on every hull, deck and PH item eventually fail.
If you have great PM and there is never an errant drop of water in the core , you are alone on the planet.
Most folks work on leaks after they have developed , it seems too much effort to pull the windows , windlass ,hand rails and everything else that screws down or bolts thru.
Plywood and balsa rot when subject to leaks.
Quality core material does not.
So with a good foam core boat your boat may leak, but not rot and require vast rebuilding to cure the damage