> documenting open-source code for free

Foundations that own the open-source projects are allowed to use volunteer work by law. Corporations with a for-profit interest doesn't.

> or answering a stack overflow question?

This one is more tricky. But it depends on who asks the question? It is an individual to get help on a problem? Or is it part of the ways of working of a company to avoid hiring experts? Evaluating intention it's usually hard.

Yeah, it's kind of like wondering why someone would make an open source project better when the person that owns the repo gets all the credit. Or all the competitors they might be inadvertently helping out by improving the project.

Sometimes it's nice to just make things better.

With an open source project, I can fork and use the code for myself and contribute back to the project.

But if I spend a bunch of time fixing AWS docs, it's not like I have any need to fork it and use 8t as documentation for my own AWS-like service.

Improving an open source project's docs aren't likely to help you, either.

Intro-level documentation changes are the most common pull requests I get on any of my projects. And the people making them are not the ones being helped by intro-level docs.

It's a clear case of experts helping beginners.

partially because you're presumably paying for the amazon service, but not necessarily with an open source project. one of the ways some people 'pay' for using an OS project is by helping in forums/docs/etc. presumably, the money you're paying for amazon services is/should be going in to their documentation.

also... with an OS project, I can actually get the code and see how it runs, test patches, etc. I can't actually do that with their services, and any docs I might contribute would be guesstimates as to how things actually work, vs how it actually does work (and what's intended), which would/should come from the company that actually owns the code in question.