They aren't paying for software they are paying to solve a problem (at least in the case of business software). That is where the value is.

Even with free or open source that comes at the cost of knowing how to operate it and even get it working on your machine in many cases.

What people (who are not tinkerers and even tinkerers that don't have the time) want is to not have to think. Let's say they want to have some free software working on a cpu that doesn't have it. They don't want to spend the time to read anything and install anything. Everything takes time. They would rather just pay someone and be able to get started (maybe even with a little hand holding). That is where someone can make money.

If you can write anything that can automate any process people will pay you for it and they should. You have solved a problem for them.