By running this query and comparing the first 4 months of this year to the same months in past years, a downward trend in activity becomes apparent.
Of all these the downward trend in votes, users, and posts are most concerning, the fewer comments might not be a bad thing although that does reflect much less activity. Fewer review tasks might also be a good thing if that means that people aren't close voting for silly reasons.
In the four years since I joined this site, at least three very active users closed their accounts, and other very active users have become much less active. Not surprising -- people have lives outside of TGO-SE and those lives become more demanding, for example, as careers develop.
Other users have joined and become very active (e.g., the OP), and older users have become more active (e.g.,@Sue), but my impression is that TGO has not attracted enough very active newcomers to replace those who have left or become less active. Thus, not only fewer questions are asked, but fewer answers are written, which can be off-putting to people who are interested enough to try out TGO but do not find an exuberant community.
My conclusion is that we discuss whether we are unconsciously making TGO too narrow in what is on-topic. We've had this discussion before, but with a different focus: What is off-topic? The focus of the discussion I am proposing is: What is on-topic that we have been ignoring?
I also suggest that someone answer this question, because I think I edited it down enough to be answerable at least in part. The same OP has extensively edited his second question to a point where I can't edit it further because of lack of knowledge. This new OP should be encouraged, not discouraged by being ignored.
The focus of this answer is different from my first, so I think it is better as a stand-alone answer.
We have to be more tolerant of the defects of questions by newbies. The newbies of today are the Liams of tomorrow, both on this site and in the greater Great Outdoors.
A snap reaction to this will be, I suspect:
What, lower our standards? Never!
English Language and Usage faced a similar problem (but theirs was too many elementary questions), and caused the creation of English Language Learners. TGO does not have that option.
We need to be more nurturing, more willing to edit questions instead of downvoting them, more careful of dismissing questions as duplicates, more accepting of what we, as experienced outdoors-people and gurus, consider elementary questions.
As for the duplicates, I have looked at many, many claimed duplicates, and found few of them truly duplicates. Most are similar, but not duplicates, and their duplicativeness could be fixed by an edit. Sure, we ask the OP to do that, but it must be very off-putting for a newbie, particularly when the question isn't truly a duplicate.
So, think hard before hitting close because duplicate button!
Another suggestion: There is ample blank space to put in the winning photo of the month on the first page of TGO. Can we do that? It would attract attention.
And maybe we need a "missionary moderator". If so the OP of this Question would be ideal.
As @ab2 said, if there are good ideas as to topics to tackle and users with experience in that topic, that want to promote it, that's great. However in general I don't think we should worry too much about these statistics due to a lack of practical implications. There have been times when people were dreaming of graduation, but since the no-longer-recent change in the graduation process, that's off the table. Looking at this graphic displaying daily questions and visitors by community we are quite well off (if you have trouble finding TGO, it's right on the 10000 line first from the left). We do act as a knowledge repository and if someone has a question, it gets answered. We still get good questions and answers. In my opinion we should accept and embrace being a low-volume community instead of stressing about it - after all it's TGO, people well served by our community should automatically spend less time in it by being outdoors :)
