Any benefit of thick concrete walls other than weird flex?

AFAIK modern building materials are better for environment, insulation, repairs, build time and cost.

Source: dad was a builder and inspector for 50 years in eastern europe. I’ve grown up in german house from 1890. He’s helping to work on my “cardboard” house in NZ now. Big aspect of course is - houses are built to the local conditions and market, but he loathes block/concrete houses back home. They are being replaced by cardboard homes too.