Male displays and ornaments are not necessarily for females alone. They also signal other males. Many mating exhibitions are assessment displays which allow females to choose a mate based upon a male’s place in the dominance hierarchy of the social group.
At least in some ways, competitive males are fit. Prowess in battle is a better indicator of overall health than a long tail.
Male elephant seals are huge: 3 to 4 times the size of a female. The very largest and strongest dominate, gathering harems on breeding beaches. In some breeding seasons, a mere 4% of the males in the group perform 85% of the matings.
Because elephant seal males greatly outsize females, most any male can mount a female, which can offer little physical resistance. A female elephant seal can object to being mounted by loudly calling to alert other males. If a subordinate male has mounted, he is soon sent on his way by a more dominant male.
The females of many species prefer dominant males. A domestic hen favors a dominant cock.
Some females are more immediately practical, preferring what a male can do to rather than how he looks. Female pied flycatchers prefer males that secure prime real estate at the nesting grounds. Their dominance is well grounded.