This is correct. The long-term companies in the building market either focus on industrial/commercial, are high-cost, or otherwise "barely get by". If you actually run the financials, they're not as high margin as you think.

And the opportunities for cost-savings have often already been done (simplified design, cookie-cutter, etc).

And every single time the housing market even slows down, tons of builders go bankrupt. Many you've never heard of.