Correlation between variables that affect engagement rates. Part 1
On the Internet, you can find a bunch of articles that address the question: "What affects the ultimate Social Media engagement metrics?". You will read about likes, coverage, comments, ER, ERR, and other metrics. But the point is that this is just a part of the truth...

If you attempt to compile a universal model that focuses on involvement as the ultimate indicator and some variables as drivers, then such a model would be incomplete and non-universal anyway. In fact, things are a lot more complicated than that. Just check it out:

• Theory: audience engagement is always converted into sales.

Practice: we experienced cases where an account made good sales with almost zero activity. And the opposite case: people clicked the "Like" button below the posts, left tons of comments, but still it brought no sales…

Theory: large coverage converts to large sales.

Practice: you can get huge coverage from Reels, but you won't sell anything. And you can easily outperform your sales plan with a small audience of 100 people.

Theory: the more likes, comments, and followers, the better the account is.

Practice: It's not the number of followers that matters, but the quality of them. If you believe the common opinion without a doubt, a nasty idea to "push" the activity may come up to you. Of course, potential leads should see that your account is "alive", and they will understand your trick right away, then you can forget about any trust.

Theory: I'll do posts regularly, every day, and there will be followers anyway.

Practice: It is true that consistency is important, but the quality of your content is still essential. You'd better think more about the content and switch to daily stories, regular live streams.
By the way, we've proven from our own experience that the most engaging post format is the carousel. Just recently, I came across a supporting article by colleagues from Hootsuite (https://blog.hootsuite.com/instagram-engagement/)

Theory: I will be making content rarely, but it will be very useful. The audience will understand and appreciate it.

Practice: It's just as hard to recover coverage and engagement rates as to achieve them. If it is really that hard to make your content, add something less difficult into it, or else people might think that your account is "dead".

Theory: I'll just be making good content and it will lead to higher coverage and engagement rates.

Practice: I can indeed agree with this statement, but with a remark. Good content must “land” on the right target audience. Our ultimate goal is to impact the way followers act and what targeted action they take (it might be like, re-post, subscribe, or buy). And there would be no success without the right target audience, even when you turn to the best creators.

Yes, things turn out to be quite different in real life than they are in theory. In each case, you have new input data that can drastically change the result. But that's how your expertise grows, so just enjoy it.