Yeah, it’s a real concern (at high tide, the area around it is flooded), but SpaceX has traditionally addressed such things with a “we’ll just rebuild or adapt

Yeah, it’s a real concern (at high tide, the area around it is flooded), but SpaceX has traditionally addressed such things with a “we’ll just rebuild or adapt if/when that happens.” They built a huge, thin-gauge horizontal assembly building right on the old crawlerway at LC39A in Florida right by the launch pad. It could well be destroyed if a fully Fueled Falcon Heavy (or Starship) explodes or if a Cat 5 hurricane gives it a direct hit. Unlike the more hardened historic VAB that NASA uses. But SpaceX built it quickly and cheaply and it has stood for most of a decade already, so it seems to have been a fairly good decision so far.