Why is paper made of tree bark?

So far the simplest material to make paper is thinned, crushed and renewed tree bark... Tree bark has qualities to be able to tear, break, and most importantly be able to be printed on easily to make thicker, different colored, or different shaped paper. No other material that is as often found and that has more in quantity in them is able to be thinned down or made simple enough to be used by the entire world... Therefore tree's are the simplest source to all the paper that is in your household, work area, school, or anywhere else on the planet...