The auto-moderator response that triggers for every new question contains a link to the rules and asks users to read it before commenting. Because this is reddit, the average user does not read these rules and usually violates them. I will quote the relevant part here:
Answers in /r/AskHistorians are held to a higher standard than is generally found on reddit. As detailed in our rules, answers should be in-depth, comprehensive, accurate, and based off of good quality sources. In evaluating answers against the rules, the moderator team is looking for responses which are in line with the existing Historiography on the topic, and written in a manner respecting the Historical Method.
Users come here for the experience laid out below, not because they are
asking you to Google an article for them, or summarize a Wikipedia
page, and as such we expect that to reflect in your responses.We remove answers which do not meet those expectations, as well as
cluttersome comments which do not contribute to informative historical
discussion. We expect that users will have familiarized themselves with
the following rules before posting, and moderate the subreddit
accordingly. We remove answers not in compliance, both with and without
notice or warning.
If you ever catch one of those deleted answers they are, usually, linking to wikipedia or quoting something they heard once from their roommate's cousin who watched a youtube video. To give you an idea, some of the best answers from this subreddit are written by legitimate experts in the field: for example iphikrates (I'm not tagging their names as they don't really need to be summoned here) is an expert in ancient greek warfare and a lecturer in ancient history for a university. sunagainstgold is a published author (behold: https://www.amazon.com/How-Slay-Dragon-Fantasy-Middle-ebook/dp/B08LDZPJSS)
etc.
Obviously people can answer questions successfully without that level of knowledge and expertise, but that should give you some idea of what people are looking for. In addition, even though you don't need to be an author or professor in the subject, it's still a relatively smaller pool of potential responders, and they need time to craft an in-depth answer.
In addition MANY questions (particularly interesting ones) have already been answered to some degree. No need to reinvent the wheel if the answer is good, I've almost gotten into a habit before starting work in the morning to spot a couple of interesting new questions and link to a past answer if I can find one.
On the contrary, questions do get answered. I refer you to the Sunday Digest, which compiles all such answers over a given week. For the week of 2022 May 9 to May 15, I count 146 (+- 3) answered threads. Some of these questions have received multiple answers, so actual answer count is a bit higher than that.
The problem is that it takes time to write an answer meeting our standards. I'm someone who works from home and sets my own schedule, so I can skive off work as much as I like - and even if I do that, it still takes me four hours from the time I spot a thread to the time I hit the post button.
Now, consider that the vast majority of our answerers have lives to live and jobs to do. In some cases, some are even teaching what they write about. And some answers will need more than four hours to write about, especially if the answerer decides to go on a deep dive on the subject, or if it's one of those questions where they don't quite know the answer but know how to find it out.
In our last flair survey, the single most common reason for not answering a question was lack of time. And by 'single most common', I mean that it outnumbers every other reason put together, several times.
Thus, we appreciate your patience while answerers go into the scholarship to provide an answer. We are quite greatly aware that this is not the usual browsing experience on reddit, which is why we have multiple possible channels to reach already-written content. Those are listed out in the AutoMod autopost at the top of every thread, and are reproduced below:
To add to the points that have been made: In fairness, intresting question is subjective. Just becuase one hasn't cuaght a lot of attention (via deleted comments or upvotes) doesn't mean it isn't intresting, just might not be for you.
As Dan has pointed out, AH gets a lot of answers each week, we also get a lot more questions each day. In last 24 hours we got over 80 questions (not including this, the ones in short answers thread and the new short answers thread) so there is a gap but there is plenty here that I hope you will enjoy, including regular threads like Saturday Showcase, Friday Free For All and Tuesday Trivia
Now why have the threads that cuaght your eye (and others) have deletions? Some will be the usual gets deleted things: trolls, off topic (including jokes), spam, bigots and so on that nobody needs to do. The "where are all the answers" also deleted. Alas reddit's system doesn't take the deletions into account so I would recommend the browsers extension that DanKensington provided a link to, helps know which ones have an answer.
As OldPersonName mentioned, there are also the ones that attempt to answer but fail to do it to the standards required. We ask for proper answer i.e accurate, in-depth and comprehensive. not variations of "google it" or "I found on wikipedia", no anecdotes. One liners might have the right answers but aren't helpful for the person asking the questions. You can have really good sounding answers that are based on out-dated information, bias or just outright wrong.
The attitude here might be summed up as "better no answer then a bad answer." There are so many myths around history (Dan often dealing with didn't drink water as unclean myth, my era has the novel and novel backlash problem) and someone getting such a myth as an answer doesn't help them understand the past better but instead leads them away from it. It stops the "first answer that seems vaguely right" wins and gives those who put in the research and the effort (the four hours to work up an answer that fits into one post is also my expirence) time and space to provide that accurate answer.