La Sagrada Familiar uses steel reinforced concrete (though technically it's a minor basilica, not a cathedral)
https://blog.sagradafamilia.org/en/divulgation/construction-...
The place has a touristic appeal and will be probably exploited for Mensajeros de la Paz (the quickest to see its potential, appear with some money and take the keys), as another similar Christneylands are, but the fact is that no sane architect wanted to be responsible of it.
This is a category mistake, no? A cathedral isn't an architectural term, but a designation granted to the central church of a diocese (i.e., the seat of a bishop, hence "cathedra" which means "seat" in Latin). A basilica is both an architectural term and a designation.
The self-correction was somewhat tongue in cheek, as the real mistake would be from the article, calling a homemade Church a cathedral.