Lots of competition compared to what?

The fact is, if you can write code, you are a very small number of people in the world. If you are good at it, and enjoy it, even smaller.

This is the point the author it trying to make, you are an an amazing position in history, you can do great things, so much easier than anyone else. In the past, you would have had to have an army. Now, just with your skills, you can do something truly amazing and world changing.