You're gonna have trouble distinguishing semantic and literal equivalence. A more useful measurement is "logical equivalency", if A, then B. And we can see that if you want to have kids, then you would like to have kids as well. So the question is, should "would like" be accepted as an alternative for want?". Well, consider:
We want to be wanted *We would like to be would liked
So, "want" has the meaning of "would like", perhaps in any case. But "would like" does not always mean want. I dunno if that's convincing, but that's why I feel like it's best to separate the two. That, and "would" is not a separate word in French ever, and there is a specific tense in which you should be more inclined to think "would". This is not the case for the present tense.
TL;dnr: Translate the present as the present so it sticks in your head correctly, and then when you know it, use whatever semantic equivalence for your own translations as your prefer.
That may be true in English but I went to three different French dictionaries and all three listed want as a definition of voulons but none of them listed would like.
From that I take it that would like is not a direct translation of voulons which is why Duo marked it as incorrect.
In my view want carries the possibility of much greater desire in English than would like. It is more expressive and personal to say want.
A bureaucrat will say to you we would like you to do x. He will not usually say we want you to do x because it is more direct and has more personal commitment.