This article points out that not only do social media sites have algorithms that limit the audience of your content, but there are also people behind the scenes doing even more string pulling. Some people see this as just the price of doing business. Others see it as a sign that many tech companies need to have an exorcism.
I think the big takeaway should be that very few things are within your control. This is true in social media, sports, and chainsaw juggling, as many emergency room doctors can attest to. Many companies would love to force people to adore their content. For instance, it is not uncommon for a Hollywood studio to spend millions of dollars both making and promoting a movie, only to have it seen by five people. Similarly I have seen businesses spend a lot of money on promoted posts only to have the comments for that post filled with lewd suggestions about the company CEO and various farm animals.
For the most part, all you can control is the effort and attention you put into your content. But if you focus on that instead of the many aspects of social media you can't control, you could achieve some pretty impressive results.