Here is one explanation. He writes that it will be better in 2022 or 2023.
https://www.google.com/amp/s/www.forbes.com/sites/billconerly/2021/05/22/why-lumber-and-plywood-pric...
https://www.google.com/amp/s/www.forbes.com/sites/billconerly/2021/05/22/why-lumber-and-plywood-pric...