I'm a fan of brutalism, so I do like concrete buildings and find them interesting, but there's also a good case to be made about mud bricks, which the author aludes to. Yes, you'll have issues building 10-storey high buildings out of mud-bricks, but it's definitely possible to build structures (like barns) out of them that can easily last more than 100 years, without the builder having to have a civil engineering degree. I've seen one such structure with my one eyes, built by my grand-grand-father who was a peasant. The only thing you have to be careful about when building stuff out of earth is water infiltrations, otherwise you're good.

Buildings made out of earth are also better heat insulators compared to concrete. My grandma's house was always cool in the summer, while my appartment which is part of a building made out of concrete wouldn't be livable in the summer without AC.