May I suggest that marking a question 'answered' makes it more about the person asking the question (eg, what they thought they needed) and less about the journey?
What about the SCFer who wants to add an alternative answer? Or, a followup question?
To mark the question 'answered' is to mark it 'do not bother adding anything important to you'.
If you 'read through an entire thread' and see that the question is unanswered, that would be a good time to add even a simple message (eg, 'I would also like to know about this') to bring the thread back to the top of the queue in the [Recently Active Forum Topics] list and in its forum.