It should be. But people's expectations differ when it comes to relationships. Some people want nothing but love, attention and care in a relationship. For them, it's enough and they'll love anyone who gives it to them, in kind.
But for some people, love alone is not enough. Some people expect love, and a whole list of other things in a relationship.
For some people, they need;
Love
Money
Their spouse to have a nice body
A good sex life
And so much more. Some can't have one without the other.
Basically the answer to your question will vary with who you ask. I feel love should be enough but again, that's just me.