[sgbuffett]

You cannot use the word necessary without saying its necessary for what?

Necessary  to stay alive?
Necessary to be happy?
Necessary to take care of you when you are old?
Necessary to provide for you?

Just asking people whether something " is necessary" is ill defined way to do a survey. It is meaningless  because most will answer NO because you won't die if you don't get married.

On the other hand "eating food is necessary" because you will die.

There are very few things that are absolutely necessary food, water air sleep.