Chasing the top is not rational when considering the very rational fact that the top has options.
I'm taken, but if were single, I'd rationally consider myself average-looking to decent. I would not find it rational at all for me to chase a supermodel (if beauty was the selector), I would in fact not try at all. Because rationally, some things are too good to be true.
I would correct that to *chasing the top can be rational under certain assumptions.
The worse the inequality gets in society, the more rational it is to chase the top, in fact - specifically for women. As I wrote in another comment, it can be better to be the Nth wife of a prince rather than the first wife of a commoner (if you're optimizing for the survival/fitness of your offspring, albeit unconsciously).
I'm taken, but if were single, I'd rationally consider myself average-looking to decent. I would not find it rational at all for me to chase a supermodel (if beauty was the selector), I would in fact not try at all. Because rationally, some things are too good to be true.