Scientist Oliver Bendel has warned an audience at the Second International Congress on Love and Sex with Robots (sadly that is a thing), that it’s because they’ll never tire.
If issues of robot ethics aren’t addressed before these sentient Fleshlights hit the market, they could either screw us to the point of physical exhaustion, or be so much better at sex than real people that humanity might stop boning entirely.
Would a roll in the hay with C3PO really be that much better than locking legs with a biological biped? Consider how easily present-day tech companies soak up user data. Now apply that level of intimate knowledge to an intimate gear-grinding liaison. Such a bangbot might, as Bendel notes, be capable of using that information to seduce humans.
Given the present state of teledildonics (the unfortunately named industry of internet-connected sex toys) cybergigolos are a long way off. Although if human stupidity is any indicator, we won’t both answering the questions around their ethical construction until it’s already too late. When alien visitors finally reach Earth, they will find only a barren wasteland of broken down robot prostitutes and the neglected remains of the dumb, fleshy creatures they were too good at serving.