Yes but they don't leave it at that. They dig up the roots, stumps everything up and pile it up and grind down and ship it out.

Sustainable forestry would only take out some of the trees, leave the stumps and replant. The forest would still look like a forest but only a little sparser for a while. there are studies proving this leads to greater yields.

Not much when the slash site dries out so much that newly planted trees fail. Happens here in Central Europe, as recently there are dry spells more often. Foresters have to (very reluctantly) accept that cutting everything clear won't work.