Comment by wrfrmers

Lumber is quite a bit lower quality than it used to be, because we're no longer using old-growth timber. Less dense wood burns faster, as does the laminated strand board that long ago replaced plywood (unless you're really fancy) (and toxic fire retardant treatments be damned).

The low cost of lumber is one of many things in America that don't make sense economically, but that persist because of momentum, with each generation receiving an inferior facsimile of what the previous ones knew. See also: car-centric policy (from infrastructure to gas prices) and retirement planning (pensions to IRAs to nothing).