Yeah, I will add that things weren't overbuilt back in the day just because they "built things better" (although sometimes they did) but because the engineering

Yeah, I will add that things weren't overbuilt back in the day just because they "built things better" (although sometimes they did) but because the engineering wasn't advanced enough to build them with lower safety margins (this is a simplification). There's a saying in civil engineering that it's not hard to build a bridge that will stand but it is hard to build a bridge that will barely stand. We could still build things that way we just choose not to as it generally means things cost more, or have worse performance (more conservative limits), or both.