I believe one of the problems it solves is that steel has a tendency to erode over time. Hence major infrastructure failures. If structural elements can be made to the same strength as steel, using HW, which will not erode at the same pace of steel, than the expected lifetime of a structure increases and that is solving a real problem.

Wood is also well known for degrading over time. Their process may prevent some or all of that, but it has yet to be shown from what I've seen.

AFAIK it does solve a problem with steel, tho: Energy expenditure of production. You cannot make steel with heat generated electrically. At least not directly. Energy dense fossil hydrocarbons are powering furnaces today. You may replace that with generated hydrogen, but I am not sure the math checks out on a global scale.