Mills are the issue, not timber. There's an excess of raw timber right now, all of the wood from the wildfires in the PNW last year is being salvaged currently.
it's not just firewood supplies (not sure how much that impacts the market, and the PNW has a more or less permanent fire season each year now anyhow) - The market has been glutted with raw timber for a decade. There has been a huge oversupply for quite a while. This continues to today - just because lumber mills are making money hand over fist doesn't mean raw timber producers are.