Thanks yeah I came here to post this. Not only are trees farm-grown for paper/wood products, but importantly there are more trees now in North America than in 1850 thanks to more efficent planting and better resource planning.
It's very likely that due to deforestation for agricultural purposes, there are fewer trees. But paper products are a 100% renewable resource and the wood products industry is actually on top of keeping things replanted etc for a long term crop/resource point of view. So the western world need not worry, it's all the literal dirt-poor farmers in the Amazon who are burning up forest land to plant crops and graze cattle on notoriously nutrient-poor soil. You can help with this by stop eating McDonald's beef products most of which come from that region. The box and bag your Big Mac came in however, were probably made in the USA with renewable materials.