All around the world millions are declaring their undying love, singing paeans to someone's beauty, describing a person in wonderful, perfect detail while thinking "I could do worse".
People don't just choose the richest or the prettiest partner or the one with best personality. Most(all?) people settle for someone. Someone within their proverbial league, someone they can strive for without too much work/money/selflessness. People are lazy, scared, generally incompetent and unable to face the reasons behind their choices. No one's together with a perfect 10, everyone's married to a 5 and everyone knows it.