First off, nothing was done with the intent to harm you. I get that it can feel that way sometimes, we were all new users at one point or another.
The mechanics of the site mean that 5 users who have sufficient reputation, agreed that your question was off-topic for the site.
I see a couple problems with the question.
1) It is not properly constrained. With the exception of the items you exclude an argument could be made for a multitude of options.
2) The question contradicts itself. As one commenter mentioned the thing can't be truly required for their survival if they have existed prior to this trade starting.
3) We don't know your setting. What goods do they have available to them to trade?
Given the above, I don't see why they need group B to kick-start their
If you can't see a reason that they would need the help, and you know everything there is to know about the world, how could any of us come up with a reason other than throwing random ideas out as answers.
All in all, with what is provided it would be impossible to define a "best" answer.
Keep in mind that SE is not a forum, its not a place for people to brainstorm for you (although we do quite a bit of that in chat if you'd like to brainstorm there)
Check out this help page for more information on how to ask particularly this bit:
General guidelines for all questions:
- Must be specific and answerable: What problem are you trying to
- Must include context: What are you trying to accomplish?
Context gives people writing answers an idea of what your end state
will look like and why you want to get there.
- Must include restrictions/requirements: What will make one answer better than
another? If any answer is equally effective your question is not
- How can this be executed? What tech, timeline, magic or other criteria apply to the situation.
- Should include research: What ideas have you considered, or what information have
you already looked at or failed to find?
Response to comments:
If you see bad actors, or at least bad actions please flag them for the moderator team to review. The site has gotten big and we just don't see everything that happens on the site. We try diligently to enforce the Be nice policy, but if we don't know about it we can't address things. This goes for everyone, please use those flags
One benefit to making sure items get flagged is that bad actions pile up and help us identify bad actors, this is how we identify people for suspensions and warnings from the moderator team.
It is an agreed upon point that on world building there is very rarely a single correct answer, you are right about that.
Reading your question though, I struggled to understand what you are really looking for, in essence, what problem are you trying to solve? Is it some trade good that makes it possible for them to get clean water? I think that is a very different and clear question. As I read the question now though it comes across as: I have two groups, one has more technology than the other, what can group X trade to group Y that group Y absolutely has to have?
This, to me, is asking us for ideas instead of asking us to help fix a problem.
In short, my personal take is the question would significantly benefit from increased clarity on what problem you are asking people to solve.
To your point about other questions being "worse" ...you're probably right. Again, we need the community to enforce standards and on a site like WB that gets challenging. If you think something is off-topic flag it so that it hits the review queues.
I can appreciate your frustration, I remember being new when the site was new and after a lot of effort put into a question to have it closed can be quite frustrating. I learned and it was painful and took some time.
I definitely suggest utilizing the sandbox here on meta or visiting the chatroom. In a lot of cases questions may not be a great fit for the SE format. It doesn't mean they are bad questions, it just means the system used around this place isn't flexible enough to handle a lot of things.