Actually that confirms the point; the old building was clearly state of the art for the time, and the new building is a cheap rush like student dorms sometimes are.

No, there are many buildings in London surviving that were built simply to get the money when they were demolished to build railways but it never happened, and they are still standing. 19th century buildings were mass produced, not always very well.

Examples? Presumably you're not claiming the Citizens Bank building from TFA is such a building, and mass-produced 19th century buildings might look quite different from it.

I dunno, there's a lot of cheap 1880s "workers cottages" around here which have nonetheless been built with a lot more style and care than the average new building.

Survivorship bias means that the only objects available for comparison are ones that bias the comparison. For example, the brick buildings from 2,000 years ago were built way better, because look at this brick building still standing that was built 2,000 years ago, look how great it is! Of course, the bad brick buildings built 2,000 years ago can't be found because they crumbled a long time ago.