Philosophers are trying to make the story that humanity tells about itself better.
You are pretty much constantly thinking thoughts that, in one way or another, you inherited from philosophers. You don’t see it, because philosophical exports are the kinds of thing that, once you internalize them, just seem like the way things are. So the reason to read Aristotle isn’t (just) that he’s a great philosopher, but that he’s colonized large parts of your mind. Not everyone is interested in learning about the history of philosophy. But if you are the kind of person who is not happy about having delegated some of your most fundamental thinking to other people; if you want to go back and retrace those steps to make sure you are on board; if you want to take full ownership of your own mind, well, in that case the history of philosophy might be for you.