the mods desire to keep the discussions on target

Not just that; the whole reason is to ensure that only the good stuff gets through. The low-effort stuff, the 'lol just google it' posts, the 'here's a book I read ten years ago and just vaguely remember or just skimmed its Amazon description' recommendations, the Jared Diamond shilling, the anecdata, the racism - all of those, we [remove], in the specific aim of getting something you can actually learn from. None of that thing that happens on AskReddit, a thread that asks "Doctors of Reddit..." but all the responses are "not a doctor, but...".

Of course, this impacts the browsing experience, which is why we have a whole bunch of solutions for the newcomer, all of which are detailed in the AutoMod autopost at the top of every thread; just check through them. Good news for you, it's just turned Monday over at this end of the world, which means the Sunday Digest for last week is nice and fresh, thus you've got some nice new content to browse over there.

Should that not be enough, the usual recommendations are r/history and r/askhistory.

seeing a great post with nothing but deleted comments is pretty annoying

There's no guarantee that any of those posts were answers. If they were deleted, it's almost guaranteed that they weren't.

The answer to your question is yes, there are subs where you can get information about history from random people who may or may not know what they're talking about. The mods here seem to be suggesting that if you post a question and don't get an answer, asking random people isn't a reliable way to get an accurate answer.

Might I point to the AskHistorians browser extension that will show if a question has an actual answer? Or the reddit r/HistoriansAnswered

The rules aren't particularly strict. Use the threads for answers rather then jokes, don't be a jerk, don't spread racism or conspiracy theories and provide a proper, in-depth answer. That there so many deletions says something.

People come here hoping for a proper answer from someone who has done the research, people write the answers here knowing only proper answers are allowed and that it isn't "first to post wins". Checking the texts and writing a proper answer that doesn't just go "yes/no/this person did it" but the how/what/why (or explaining why the question comes at it with flawed assumption) takes time so can be a question isn't answered for 24 hours. Or someone who knows that subject simply isn't available with their schedule to answer that question.

Sunday Digest shows that many many questions get answered each week but yes sadly others do go unanswered. The only way that can be got around is either we capture experts and force them to only answer AH questions or we drop the proper answer requirement, at which point we negate why people come here.

Other people prefer the other subreddits you have been linked to. The question is do you want an informed, correct answer or taking a gamble that the answers you get will be right or if they will be based on not always reliable wiki/google, out of date theories and research but without being able to tell which is which.

R/Askhistory

R/Askhistory