I think you don’t get the point. It‘s about that if we are only trying to optimize for outcome, we will loose what makes it more than just biological. I don’t see how it makes sense that a women using a dildo is in any way similar to a human to human interaction, it’s more than just getting off right?

It's not limited to men. A lot of feminists are also vocally against the idea of female sex bots because it makes them feel insecure.

There's a difference in scale and potential consequences though

What if there were some robot with superhuman persuasion and means of manipulating human urges such that, if it wanted to, it could entrap anyone it wanted to complete subservience? Should we happily acquiesce to the emerging cult-like influence these new entities have on susceptible humans? What if your parents messaged you one day, homeless on the street because they gave all their money and assets to a scammer robot that via a 300IQ understanding of human psychology manipulated them to sending all their money in a series of wire transfers?