I did some research on the root of the English word 'love' and the French word 'amour' to attempt to find the roots of them. The farthest I can find back is two Proto-Indo-European words, "Lewb" meaning both to love and to cut off, and "Am" relating to the nurturing love between a mother and a baby (this may be wrong though- this is just what I've found). So is there any reason there were two words in this language for love? Is there a difference or is it simply two words that formed?
It should be noted, anything about Proto-Indo-European is purely hypothetical, based on comparing all its different descendants. That is, there are no Proto-Indo-European people we can go up to and interview about "what is the difference between this word and that word, exactly?", and there are no written inscriptions talking about a particular word and how it's used.
What we do have are texts in descendant languages that we can compare, that let us know that Latin amō and Ancient Greek philéō and Hittite āssiya- and English "love" all mean roughly the same thing. But those all look very different, and don't point toward a single ancestor to all of them.
So, what does this tell us about Proto-Indo-European? Honestly, not much. Words get replaced over time for all sorts of reasons, and meanings shift, and new meanings arise and old ones die out. There's a pretty clear Proto-Indo-European root for "horse", but English "horse", Spanish caballo, and so on are completely unrelated to it due to changes over time: "horse", for example, goes back to a PIE root reconstructed as meaning "vehicle". Greek philéō probably comes from an earlier word meaning "friendly", while Hittite āssiya- probably comes from an earlier word meaning "good", and Latin amō probably comes from an earlier word meaning "mother", and so on.
Even in terms of living languages, the existence of multiple words for a concept isn't unusual. Why does English have separate words "love", "affection", "crush", "romance", "liking", and so on? It doesn't necessarily tell us anything deep and meaningful about English or English-speakers; these are just distinctions that have arisen more or less by chance, and been useful enough to stick around.