I can't imagine a relationship without passion.
It would be like sleep walking through life.
A relationship without passion, chemistry, & romance is boring!
You might as well be plantonic friends.
These types of relationships usually take place after someone has been hurt in a previous relationship where there was passion. The hurt person intentionally seeks out a new person with whom they have very little chemsitry with but looks good "on paper" in order to protect themself.
As time marches on they become bored to death and usually end up hurting someone that cares deeply for them.
"Playing it safe or settling" in order to avoid pain rarely leads to happiness in the long-term. It is possible to have a passionate relationship with someone who is also good to you.