What IT careers brings in money rather than cost a company money?

I think you're looking at it the wrong way. When I was in production planning we understood that there are value added services and non value added services. Some of the services you describe fall into the value added category, like writing and maintaining code. Anything that adds value to a product or service is... value added. Coding is making something better.

Paying for outside QA processes would be an example of a non value added process. Doing (arbitrary) documentation (like customs paperwork) is not value added. Creating a user manual for software is value added.

But to answer your question, SEO seems like something you're looking for. I'm not sure sales counts, considering it's not really a STEM type job.

I think that's a terrible way to look at an any type of career. Any job can be outsourced, the important thing is if the person brings value to the organisation.

In sales or sales engineering it is easy to measure your impact. I cost $X and I bring in 10x in revenue. But it is a lot harder to measure the value of someone in a back office or development role, but it doesn't make them less or more valuable to the organisation.

Every company defines value differently. I work for a university, we have desktop support engineers who could be easily outsourced if you only looked at them as low level techs, but they care about our mission, about teaching, research and learning and put in 10x the effort that an outsourced low cost tech would from one of the big firms.

Sales Engineering is the best. You get to build things to help customers and generate revenue. You get to code and present. Learn your customers business and teach your businesses product.

Outsourcing engineering can result in friction and needless overhead. Strong companies will also prefer to hire engineers who believe in the company's mission rather than just a bunch of merceneries. I understand what you're trying to ask but you seem to be looking at it the wrong way.

It solutions are great if that’s your product. It sucks if the solution is only there to support the companies other revenue generating product. Really unless you are a programming company programmers are a cost center

Depends on what that particular company invoices its clients or customers for.

You want to contribute to building or maintaing that.

In product companies, software development creates value that company sales.