Consider this suggested edit to this question. The question regards a particular error seen when attempting to embed youtube videos for iOS. At time of writing, there are no answers. The edit is a major rewrite, but the root question/issue is exactly the same.
Apparently the edit was sparked because the user who suggested the edit had the same problem, wanted it solved, but wasn't satisfied with the question as it stood. Editing was their way of asking their own question that would otherwise have been a duplicate. They also put a bounty on it.
On the one hand, this is good. The question's better than it was before and more likely to be answered well. On the other hand, there are aspects that don't fit well with the current SO model:
Should this edit even be approved?
It would not be a stretch to call it a radical change. Outside of the actual problem, nothing would really remain of the original asker's question. The editing guidelines aren't totally clear. This is well beyond the minor changes suggested as editing reasons, but certainly falls squarely within the overarching goal of making the post substantively better.
If approved, it feels like the editor should own the question.
The editor (evidently) put more time into writing the question, and has in this case committed a bounty to it as well. They have plenty invested, while the original asker just happened to note the problem first. Obviously their main goal is getting an answer to the problem, but it's unfortunate to see them get the short end of the stick reputation-wise because someone else happened to ask the question first.
If not approved, is there any alternative for the editor/bountier?
If they ask a new question, it'll be (rightly) closed a dupe.
If they put a bounty on the unedited original question they're likely to not get good answers because it's not as well written as it could be.
Fundamentally, the question is:
What should you do when your question has already been asked badly?
Looking through meta there are a number of similar discussions, but none that seemed to address the core problem:
Should I totally reword someone else's question?
This concerns post-hoc editing of a question to try and make it a better resource going forward.
What can we do for new users who want to ask a question that's already been asked, but hasn't yet got an acceptable answer?
This concerns cases where existing answers don't work -- solution, ask a new question including a reference to the original question and more information.
Adding additional info to someone else's question?
As above, this concerns questions which are similar, but not identical.
How to teach an OP to write questions? May I rewrite a badly asked question?
Similar to the editing guidelines, it's not clear exactly where this edit would fall and there wasn't exactly a definitive answer to that question.
(If there's a definitive discussion I missed, please point me towards it.)