A high value man will have no trouble finding a high value woman to lock down, and a low value man will lock down the first woman who lets him touch her. The perpetually single tend to be average looking people who cannot attract the high value people they want, and are unwilling to settle for lower value people they deem to be below them.

Most people overestimate their attractiveness, and this makes no difference to ugly or hot people because even if they add one or two SMV point to their attractiveness, their still ugly/hot. It's only people in the middle of the scale who overrate themselves meaningfully (i.e. a 3.5 thinking he can go for average women, or a 5.5 thinking he can get a fairly above average woman).

Anecdotally, almost every couple I see on the street are either hot or ugly. I rarely see plain couples.