Well, you only need some bread and water to stay alive, but survival is not our priority today. First of all, having people liking your comments is a necessity for your account's overall credibility.
People will realize that you have lots of likes, followers, views, and stuff. However, what if they see that your comments don't even manage to get a couple of likes?
The best way of getting your account restricted due to paid growth is snitching yourself out to the authorities. You wouldn't want that.
After that, comment likes are essential because so many accounts on Instagram gained their popularity through this unconventional action. That means this is a viable way, and you may want to take that route because the followers you get will be more devoted and loyal compared to other actions such as putting up consistent content.