There are dozens of brands and types. Scott, Angel Soft, Charmin, Western Family, as well as 2-ply, 1-ply (the kind that leaves stuff behind, as Charmin would have you believe) and stores like Walmart and Costco devote entire aisles to their toilet paper and maybe a few paper towels and napkins.
Everybody poops, so it makes sense everyone wants access to this toilet paper. I poop too, and yet I haven't bought toilet paper in over three years. How did I do this?
I just don't need to. I argue that it's unlikely anyone does, because there is an overproduction of paper products occurring as it is. The United States holds about 15-20% of the world's people, yet we are using over 65% of the world's resources - much of it coming from forests which is making our paper products.
Now to the point - I told you why you don't need to buy toilet paper, but HOW do you not buy toilet paper? By exercising creativity, and noticing all those paper products lying around in the first place!
At the restaurant or fast food joint, request extra napkins. When you're at work or school, create a day's worth of toilet paper on your own using the toilet paper found in the bathrooms. When you see leftover remains of toilet paper rolls sitting around, grab them. You probably don't know this, but the janitor who works in the building where you found that toilet paper has to throw it away at the end of the day if it isn't used up. What a waste!
As you can see, there are many alternatives to buying toilet paper in a culture drowning in paper supplies. Many varieties of securing the needed paper supplies as well. Remember this - you use a lot less than you realize when you make a commitment to avoiding the purchase of that wasteful product - toilet paper.