Many houses built 100 years ago were incredibly shoddily built / assembled. Have you ever looked at the foundations on old houses? Wooden piers that are lucky t

Many houses built 100 years ago were incredibly shoddily built / assembled. Have you ever looked at the foundations on old houses? Wooden piers that are lucky to last 40 years were very common. You’re seeing survivorship bias at work. Also 250/sq ft is far from cheap/shoddy quality in much of the US. And with proper maintenance just about any house built to code in most places in the US will easily last longer than the average house built 100 years ago.