Imagine a well-designed front wing, working to perfection. The airflow is happily being channelled around the front tyres, the outwash lost to the new rules has been partially recovered, and there's a strong vortex being shed from both sides of the wing's neutral section. It's a fantastic starting point, but to exploit it to the full the rest of the car has to be just as good.
It's like starting a relay with a quick runner. Sure, it puts the team in a great position, but if the other three runners can't hack it, then the initial effort was wasted. The second runner has to be as fast as the first, much like the bargeboard package has to mesh perfectly with what the front wing does.
Since the redefinition of the bargeboard area in 2017's aero changes, this piece of real estate has become hugely complex in a very short space of time. Although the intent seems to have been to reintroduce the sweeping, one-piece bargeboard pieces seen in the previous decade, today's bargeboards are a collection of intricately positioned fins, cut-outs and slots to aggressively condition the airflow off the front wing, guide tyre wake away from the opening of the floor, and turn airflow around the sidepod undercut to bring it into play further down the car.