Forums are meant to be a discussion platform, that is openly documenting problems and their solutions. Sadly most of the people don’t see the importance of the solution, especially in connection with the problem.
Depending on the topic, this “solutions” could be a normal opinion on an issue, so you can base your own opinion on it. This is typical for political and social discussions.
It could also be a bunch of recommendations, e.g. if someone needs a new device and does not know, which to pick and why.
And thirdly there are a lot of technical forums, where people ask questions and others try to find a solution that works.
In all cases, documenting not only the questions, and a list of guesses underneath, but also the solutions, is quite important, as new people may encounter the same problem and on their search for a solution they may find this board. Why should you care?
Well, it is only fair. If you as a user, post a question, there are a lot of people who at least take a look at the question. They read the question, try to understand it, and think about, whether they can answer you, or not. All this takes time. It takes even more time, to then sit down and write an answer or a guess to that person, especially if they at first try it out themselves (yeah, people do that!).
So it is a matter of good behavior, as someone who asked the question, to then also reply to the answers. Say whether it worked or not. Or if you found the solution yourself, just write it down! – so that at least those persons who tried to help you, know the answer as well.
But not only this, they are also helped by the fact, that this question is not asked over and over again, if the question is widely spread, but no answers are found; because now there is an answer – others will find it – and if not you can point them to it.
So the next time you post a question, try to be appreciative – by posting an answer, or by saying “Thanks, that’s the solution”. If you feel that it is not worth it, then stay away from such discussion boards. For all those who don’t and who misbehave like this – at least I for my part, do not answer those people anymore – even if I knew the question. And I know, there are a lot of other persons, who just think the same way.