I would think the second, the law of diminishing returns applies I suppose.
In very simplistic terms, Toyota have been very good at producing a neutral car that gives confidence, Hyundai went from an under steering car in the ‘17 spec, to a tail happy one and MSport did the opposite, tail happy to understeer. Hyundai with their resources, and drivers have improved quite a lot in a short space of time, MSport it has taken longer due to less resource.
I’m sure their is more nuance than that, but the way I see it, those are the broad strokes.