The only nugget I can reveal is that many users have bought into a social contract of rags to riches, "organic growth" from nothing, and just like real society, this is the least effective and time wasting set of rules to play by.
when there are obviously other competitors that don't take a bot approach, shouldn't be that hard to accept
There are also likely to be large, influential, account networks that are real and when used to boost a new account, very effective (I know numerous people on instagram with multiple million+ follower accounts).
All of this is similar to content marketing and link building strategies that have been effective for a decade plus.
Its more beneficial not to be more specific, and seeing that nobody else has anything to add and are more-so frustrated at the asymmetric information then its a form of validation.
But I've taken accounts from 0 followers to 10k+ followers within a week's time. All the follower's accounts are non-bots, any random selection would be highly engaged real humans, and new posts maintain around 2%-5% of the followers liking or viewing+liking without the use of hash tags at all. There are interesting skews in the demographics, worth its own article, but I'm fine without it.
For follower count alone, instagress would take months to do the equivalent, as its activity is slow and varied to avoid detection as a bot. Also the unfollow rate begins to match the speed at which it can safely attract followers, in the low thousands, if you don't have an exceptionally active niche.