I can't imagine how anyone would say that sleep is not a need. Sure, in the view of the Dhamma and the renunciate life, we probably don't need as much sleep as we currently get, but that doesn't mean we don't need sleep. Ariyans sleep. The Buddha slept. Without sleep, you will die. You need sleep.
Just as, in our practice, food is treated as a medicine for the illness of hunger, sleep is treated as a medicine for the illness of sleepiness. The patient should only take as much as needed.
Sex, on the other hand, is a sense pleasure. Attachment to sex comes from ignorance of the anicca characteristic of temporarily pleasurable phenomena. You don't need any amount of sex to survive in this lifetime. All the stress and tension released from sexual activity can be just as effectively released by other means, such as, oh I don't know, meditation."But not everyone has the luxury to be a renunciate."
I remember reading an article somewhere (can't remember the name or the author, sorry) stating that an Ariyan of any level will have already cultivated the good kamma to be born into a life situation favorable of the taking of robes. I have no proof or source, but if this is true, then that means my previous statement still stands: along the path to liberation, at some point one will ordain. I'm not saying one should take my word for it, but to me it makes sense: why would an Ariyan have any desire whatsoever to continue mundane lay life when they have tasted for themselves the freedom of renunciation?
I'm not dissing on lay life, but it's common knowledge among practitioners that ordaining is simply a better way to acheive the goal. This doesn't mean that all monastics are currently acheiving maximum benefit from the robes, because it definitely depends on the status of your practice. But there's no doubt that lay life presents many more obstacles to liberation than monasticism does. This is why the Blessed One spoke so highly of renunciation. He calls the Sangha the "incomparable field of merit for the world."
Again, no dogging on lay life, because I definitely enjoy the luxuries and privilege that goes along with being a householder (especially as a Westerner), but the challenges to my daily practice are too many to count. I yearn to one day take robes, even though I know it will probably never happen.
Just my thoughts.