If we assume that there are some people who just use Instagram for no advertising purposes, then you can understand them, but I can’t. Instagram has become more convenient for business and many people are trying to promote their account, not for profit, but for brand recognition or their personal blog. And that’s where the sales are coming from. I read about https://1394ta.org/blog/influencer-marketing/ and I can say that this is only part of the tools. Even other networks have begun to sell business accounts and Instagram is just a social network without convenient tools. So everyone is trying to disguise explicit marketing. And they succeed.