I think the appeal in a good robot/human romance to me is not 'the human can love this mechanical being into feeling romantic affection like a person' but having that mechanical being algorithmically validate the human's value to them. There's no doubt that the human is a net benefit to the robot's wellbeing or else they wouldn't bother. The robot can't love insofar as a human can love, but they need insofar as a bee colony needs a beekeeper and the keeper needs the colony, and there's a poetic and personal satisfaction in that type of mutualistic need.
Also there's the neurodivergent lens of dropping the veil of social conventions because they are inconvenient to one party and outright nonsensical to the other. That too.