Engagement groups work on and off. Now, if you, like the majority of the world, has a personal account, don't expect hundreds or thousands of new followers. You'll get the likes from the group, but that's it.
For the rest that use videos from youtube, twitter, etc., that have already gone viral, you'll get better traction.
Instagram needs to be separated into two specific genres - personal and those that copy viral content. It is extremely difficult to compete with a photo/video taken by a professional guru. So, unless you're a hot babe and have a great photographer and live in a great place, have the money to be INSIDE fancy hotels, restaurants and homes it will be hard for you to have personal viral content. ie. A homely guy/girl in the middle of Nebraska, in a pig farm or worse in an old dilapidated house with no farm, in Winter with no mountains, hills, trees and rivers nearby, and the only thing you have to wear are 3 pairs of the same looking Wrangler jeans and 3 pairs of plaid long sleeve shirts with a pair of old boots, the same old worn hat, and you just came down with a flaming rash of rosacea or broke out in pimples. Get the idea now?
This is why luxury and hot babe accounts grow so quickly. For the rest of us, or those of us handling personal or business accounts with little branding money, it's hard to compete - not impossible, just hard.
