Camping is when you go into the wilderness for fun. Survival is when the fun is over and you are trying to get out before you die.
Starting a fire is a staple of both. In camping you have things like matches, butane lighters, fire sticks, and white gas (Coleman fuel). In survival, you may not have anything except what's in your pockets so starting a fire by any means available is important.
Steel Wool (size 000, or 0000) (Brillo pads) across a battery makes an amazing display and is quite effective. Better to use a couple D-Cells because you will get a larger "hot spot". However this falls in the category of outdated survival skills. It used to be that everybody used steel wool for cleaning their steel or aluminum mess-kits so you always had some. And you had a battery operated flashlight. Out of matches? No dry tinder? Short steel wool across your batteries and have those tiny twigs (or frayed bandana, or birds nest) ready and get ready to blow.
Now with non-stick coatings on exotic featherweight titanium alloys, nobody uses steel wool except in base camp on their cast iron or aluminum dutch oven so there is no "primary use" for it and thus nobody carries it.
Dryer lint does make great tinder. It also catches sparks well (esp if it is slighty pre-charred) if you are using flint & steel, spark sticks, or rubbing 2 sticks together. so does white gas or gasoline. The advantage that dryer lint has is that there is already some in the bottom of your jeans pocket. Very few people pack it but they might put some in their pocket just in case. There are just too many easier alternatives.
If you are going to carry something camping to start you fire with, there are many much better solutions that one can make or buy. Fire starting sticks that are compressed sawdust soaked in wax are good. A cotton ball soaked in wax is handy. Pitch wood is great. Boat matches burn really hot, will strike when wet, and are water and wind resistant.
My favorite tinder is dead grass, dry leaves, or found paper trash and I don't even have to pack it.