Limestone is highly porous and sea-water soluble, so…

Yes, people in developing counties will have a hard time preparing, but it’s not like Florida is going to be able to build a wall around itself. Some places where the dollar-per-unit of costal protection might be able to afford it (thinking NYC), but other places even in the US will have a harder time practically in the day to day (hard to move ports and what are we going to do about New Orleans?) and looking to the future (mortgage/insurance nightmares.)

COVID showed that the supply chain isn’t very anti-fragile and the climate catastrophe is much more impactful.