Tell that to all the people who used to work in the US wood products industry, now without jobs, thanks to Canadian subsidies to their timber industry.
The jobs lost in the logging and plywood/sawmill business were not lost due to Canadian lumber. The U.S. Government banned almost all logging the Olympic Peninsula due to the Spotted owl. At the same time they forbade the practice of clear cut logging in the National Forests and reduced the sale of National Forest Timber. In the 1980s the Forest Service sold about 10 billion board feet of timber for logging, per year. In 2015 that figure had dropped to 2.9 billion board feet of timber. It was the U.S. Government that wiped out those thousands of timber industry jobs, not Canadian lumber.