Simplicity, complexity, and the hierarchy of detail. The real world is often not so simple as it first appears. How simple something is, in fact, depends to a considerable degree on what level of the hierarchy of features and details it displays that you look at. If you only look at the surface, or only just beneath it, then things may look very simple. They are inconvenient, though, only if you aren't interested in a deeper understanding, if you have some preconceived belief or have adopted the mantra that things have to always remain simple or else they are bogus and not truth.
Simplicity is thus a function of the perceiver as well as the perceived.
Our human minds and their capability for high levels of abstraction enable us to perceive more unified conceptual groupings on one level if we temporarily relax our focus from the complexities at other levels. And as long as we remain aware that hierarchical levels of increasing complexity exist that may end up being just as relevant, such simplification can be a powerful tool in enabling us to grasp unifying principles. That's the upside. The downside is that we are also capable of manufacturing fictitious simplicities that then have to be supported by unacknowledged or covert complexities at other levels we remain unconscious of. Either way, there is no escaping a certain amount of complexity on one level or another.