You think that the written word came before the feeling? Just because only the educated knew how to write down their feelings does NOT mean they were the only people to HAVE feelings.
Love is not created by “time and leisure”. People have fallen in love across all class boundaries, while in the most awful circumstances.
The fact that people may not have married for love and that their married love developed during their committed relationship doesn’t mean that romantic love as a feeling didn’t exist.
I think you have an extremely limited view of what romantic love is, and you also have a very warped understanding of history (especially if you think it was AMERICA that came up with romantic love).
The Western CONSTRUCT of romantic love as it is expressed in industrial society is not the same thing as the emotion itself.
The emotion is something that can arise whether you “feel lust at first sight”, whether you feel “eros” as described by the ancient Greeks, whether you develop love over time as for example many Indian “arranged marriages” develop etc. Everywhere you look in history there is evidence that romantic love existed. That in ancient civilisations people had affairs outside of their marriages because of this. That’s WHY adultery was punished so harshly. It’s not just because of sexual attraction it’s because of love.