Because a good team of software engineers can bring a lot of value. They can write a software that saves company millions of dollars. They can can make a product which will bring millions of dollars of profit. And for all that, their labor and equipment expenses will be a fraction of that amount.

There are very few professions with profit/cost ratio this high. Writers and media creator come to mind. Definitely not electricians or builders.

(Of course not every software engineer is like this. But there are plenty of $60K software jobs in US too, nit everyone gets six digits)