Money is ridiculously cheap right now. I just refinanced my house and my mortgage went down 20%, and I just refinanced four years ago. When the appraiser came he told me that he's been working non-stop since April 2020 because there are so many cash-out refinances. There are a ton of remodels near me, many of who got the money with cash out refinances.
It's not a surprise that there is a demand for lumber.