Our love for our spouses is conditional. We love them on the condition that they love us back.
How are you defining love there?
A spouse may cease to love the other because of abuse or drinking or drugs or affairs or neglect.
A child may cease to love a parent because of abuse or drinking or drugs or affairs or neglect, right?
Spouses choose each other unlike children who have no choice as to who their parents are.
My perspective: God chose my spouse; I agreed with His choice.
We raise our kids from newborn to adult and that is a completely different relationship than a husband and wife.
It is part of the husband and wife relationship. If for no other reason, my unconditional, everlasting love for my wife is based on the fact she carried our children in her womb for nine months and then invested even more time breastfeeding, changing diapers and "loving on my babies" as only a mother can. Frankly, if she
could stop loving me, I wouldn't stop loving her because she is the mother of my children.
We meet our spouses much later in life. We get to know them and fall in love with each other. It is a relationship that requires constant work. It may not feel like work, but it does take effort to keep the relationship with your spouse vibrant. And they need to reciprocate. When they don't, love slowly starts to die, piece by piece.
I'm skeptical of your conclusion.
If your wife passes away, will you love her less since she can't reciprocate? I don't think so. The love you still feel then, when there is no sex, no talking, no "fun" of any kind together, that's the unconditional love I'm talking about.