NV didnt really give it a purpose... the only burden I felt was carrying around a few extra pounds of food/drink. Sleeping never really seems to affect me. There was enough beds around where it was just a very minor annoyance. Neither were fun elements though imo.
Thats because it was badly implemented and dungeons where shallow, and map could be quickly crossed.
Loose yourself in wilderness,
Loose yourself in a dungeon,
Make thirst affect your concentration/spellcasting skill
Make starve affect your endurance strenght
Make killed creatures provide meat
Make water source provide water
Make bad food and bad water poison you lowering your stats VS not eating = dying.
And you will see how is it rewarding to plan and improvise. What many RPG fails to implement is FEAR fear of dying. If player does not fear death then all the gameplay is affected toward the "whatever" factor and many implementation that otherwise would made sense loose it.
Adventuring is by essence the reward of overcoming death fear, of breating this very challenge ultimate failure... Death, the sucess of overcoming problems and enjoying the rewards, be it in gold or knowledge or both.
Those who intuitively or not understand this very aspect are those who ripe the greater enjoyment from true RPG, and surely those who clain for hardcoe mode.
IF there s an hardcoe mode in a game i m in, IF by any way i m not up to the task for any reason (not having enought time to head in and pitch myself in), no problem, i step back.
I won t feel diminished by that, its a game afterall, and i have other more important challenges like working studying wife and who knows kids.