To turn trees into lumber you have to cut them down, transport them to a sawmill, cut them to size, kiln dry them, transport them to the build site, build a house out of it, etc.
Underground sequestration has no transport, milling or kiln costs. Just cut down a bunch of trees, dig a trench where the trees used to be, and bury the trunks.
Or, you know… build homes.
To turn trees into lumber you have to cut them down, transport them to a sawmill, cut them to size, kiln dry them, transport them to the build site, build a house out of it, etc.
Underground sequestration has no transport, milling or kiln costs. Just cut down a bunch of trees, dig a trench where the trees used to be, and bury the trunks.
Why not both?
Too obvious!