I don't think this is true. "The algorithm" is indeed proprietary, but it's much more like an AI than a tool. Facebook has it's own, so does Google, so does Twitter, so does Instagram etc. But they all operate according to the same principle.

Each algorithm analyses the information that we, the users, interact with the most, and surfaces it up to other users who it judges to be similar to us. They make this decision based on the enormous amounts of data the have on us. But the motive is profit, not explicitly to misinform (well, unless you count misinformation campaigns, but that's a separate issue).

The networks simply don't care if we're misinformed as long as we use their platforms and allow them to make money from advertisers.

If you think about the sheer volume of information passing through a social network every second, it would be impossible for any human or even group of humans to deliberately manage it in such a way that it fed a particular narrative. What you're seeing is our own bias and our willingness to believe things on zero evidence in action.