There are only so many social actions you can preform every day on an Instagram account without getting banned. You can choose to use these social actions to gain more followers, or you can use them to increase your engagement with your current followers. Instead of commenting on accounts that do not follow me, I comment on my followers posts instead.
Yes there are different strategies that work for both, however I find the best success rate by mainly focusing on engagement only. Instagram really likes it, and ranks your account higher. The higher your engagement ratio is, the more often your pictures get featured and seen by millions.
I honestly just look at the likes, pictures, and followers and can tell if the engagement is good or not. Every account is different since they are in different niches. Its obvious that an account that posts pictures of animals will have more comments compared to an account that posts pictures of gym equipment.
My goal for all my accounts is to have a 25% engagement ratio.
If my account has 10k followers, the pictures should have 2,500 likes.
There are many other factors that take place also. For example If you are posting lots of pictures every day, each picture will receive less likes.