Help me answer: Is Passion and Affection Really Important In Adult Relationship/Marriage or It's Not Necessary?

I wander how you guys see this things: do you see affection and passion as quite important features of one healthy relationship?

I find it soooo important and necessary to the point Im not sure if it's only me or other females also crave it badly.
And what of guys?

The idea of "good relationship" changes as we are growing older and getting mature,from "Young Love" where we lacked ambitions and directions,plan and program,had plenty free time and ability of spending days in bed with person we love.

Carefree love with a lot of sweet kisses,wild passion,sleepless nights,hands holding,all day chatting,to an "Adult Love" where we decide on building an empire with person we choose to share life with,relationship with much more wisdom,common sense,way more thinkable relationship where long phone calls and long morning cuddles are replaced with breakfasts in hurry,sweet talk with expenses plans,salaries and business ideas and where we most of the time spend grinding, trying to make sure we tame upcoming future and make it bright,for the sake of our kids,of course.

Relationship with goals,plans and direction  is absolutely something every normal adult should be grateful for,but at some point I get confused..

Is it okay to completely trade a passion and affection for "partnership"?
Or pinch of "young love" in an adult relationship is way to spice up the intimacy between couples since we are not robots,we have needs as humans.

Somehow I strongly believe that in world full of seriousness,bills and deadlines,you need to get "carried away" from time to time for the sake of balance needed between your mind,body and soul.

I would like to hear your opinions,men and women,both because I'm not sure if I am giving too much importance to this or not.

I also think it has a lot to do with culture we belong to and the way we were brought up.

How important that teenage passion,excitement and affection  is in your relationship/marriage  as an adult?

If no,why?

If yes,why and how to you keep it alive?