How many other things are considered necessities but are not?
New car - even though the old one runs fine & would save you $20-30K; new clothes; a new computer (my own fault) - even though all you use it for is email & surfing; etc.
It is like the difference between needs & wants. Many people confuse them. Needs like food, shelter, companionship, water; wants like the above "necessities". When we are young we express most everything as a need; hopefully as we grow older (and hopefully wiser) we recognize the difference.
Reminds me of a Money magazine article that I read long ago. It was examining the finances of a young family. The wife "needed" to work to pay the bills. The magazine added up the extra clothes, transportation, child care, eating out, taxes, etc that were required to allow the wife to work. In this particular case (not all couples would be like this one) the extra money that the wife's working brought in was basically nothing. What they thought of as a necessity was not!
ne·ces·sity (n) anything that is inevitable, unavoidable, etc. as a result of natural law; that which is necessary in natural sequence; the compulsion or constraint of man-made circumstances, habit, custom, law, etc.; logical or moral conditions making certain actions inevitable or obligatory; something that cannot be done without; necessary thing: often used in pl.