Paper mills have a smell due to the digestion process that turns the wood pulp into something that you can make paper out of. Some sulfur and other compounds make that rotten egg or day old fart smell. Often depends upon the type of paper being produced.
Kraft paper process (think of brown paper grocer bags) smells the worst. Other types like computer or toilet paper do not smell as bad. There also tend to be “bug” settling ponds like waste treatment plants (think sewage).
Wood does not want to be digested and broken down into usable fibers. The reason that there are vast seams of coal is because there were forests living, dying, falling over and building up long before the bacteria evolved that could break down the cellulose. So it didn’t rot and kept building up. That is a simplified story of course.
Here is an article from the government of Wisconsin.