After ten years, why are we still not telling folks that their questions have been bountied by good samaritans?
I can think of a few reasons why this hasn't been implemented yet. Most of them boil down to: It would create too much noise, or not be as useful as you think it is.
If somebody bountifies my question I would like to know about it because I would like to keep an eye on the activity there.
Most activity on questions is already tracked: You get notifications for reputation changes (up/down votes), for new comments on your question, and for new answers to your question.
I think half if not more of these 'bounty notifications' will just be noise: When someone rewards an existing answer or someone posts a bounty in the hopes you get a new answer, I don't necessarily need to see it. The first is not related to my question, the second already notifies me once the new answer is posted.
I understand there may be e.g. edits to existing answers after a bounty is posted but those can happen at anytime without bounties as well. If you really want to keep an eye on those, you're going to need more than just a notification whenever there's a bounty. Some third person could comment on an answer asking for clarification (resulting in an edit to the answer) without ever having to post a bounty.
If somebody bountifies a question I'd answered, especially if they are asking for more details, I'd certainly like to know about it so I can add some details to my apparently inadequate answer.
In general, asking for improvements or clarifications is what comments are for. Bounties can be used to offer an extra incentive to do so, but they're not the main tool to prompt. At least my Dutch self would first try to get that clarification by commenting only.
A notification of a bounty to indicate you should edit your answer can also have a different, rather unpleasant side effect: People may start ignoring requests for improvements in comments until they get notified someone is 'willing to pay' for more.
If I bountify a question I don't want to have to add comments under each answer that I think is close already and within reach of satisfying a "more details" bounty, but that's exactly what I do.
Again, you can leave those comments without setting a bounty too. And, this sounds like you're already selective with regards to which answers could be improved to be eligible for your bounty, and which answers don't stand a chance at all.
I for one wouldn't want a notification in my inbox if the poster of the bounty is not currently considering my answer to be close to eligible. At that point, it's just noise. Sticking with the comments allows you to selectively notify people, and not waste the time/attention of others.
There is another benefit on leaving comments on answers: You're making yourself eligible to receive comment @replies under those answers. While you can @reply to the poster of a bounty, that can only be done on a question. I wouldn't really want my inbox to be full of notifications from two people figuring out what needs clarifying in a particular answer, in case the bounty is unclear. Leaving a comment under the answer allows for direct engagement on that post, without bothering others.
If I bountify a question I had always assumed the OP would have been notified. Of course the bountifier decides how to award the bounty but I would be more than happy to receive feedback from the OP as well.
Not everyone shares this attitude of wanting to receive that feedback. Not notifying an OP means you can award your bounty in peace, without having to argue about it. There's something to be said for both sides here, but I'd go with just having the people that are open to this feedback asking for it in a comment, instead of sending out a bounty notification and prompting unsolicited feedback.
