this also glosses over the fact that some people will of had to have them as prostesis, are we really okay with the idea that people that need a leg replacing are less empathetic than people with both legs? that they are less human?
I'm really not.
This is a Cyberpunk 2020 thing - a Dark Future thing. It's not our time or our people.
In the Dark Future, Technoshock is a real thing. People are limited in their ability to adapt to the rapid pace of change, which by 2020 has been very very rapid indeed. Settled outer space colonies, full VR and VR immersion in the Net, cloned replacement limbs, cybersoldier wars, wholesale Collapse of the mightiest nation on Earth, commonplace human upgrading, Artificial Intelligence - full sapience.
And all in about 25 years. MOST people can handle it just fine. Some people cannot. But nearly everyone finds it more difficult to relate to other people in the Future.
We are seeing this in our world, today - this distancing of human contact, this virtual life.
In 2020, things that increase this sense of distance reduce your Empathy. Some cyberware has no Empathy cost at all! Some has very very very little, so you would see no difference in your empathy to others.
Some has much more and will serve to set you apart from what -you-think is Human.
On average, a relatively mentally healthy human will get a Cyberleg and will see -no- ( that is to say, zero) discernable change in their Empathy. None. For many, you could get BOTH legs and see little to no Empathy loss. Your ability to understand others, to socialize, to lie - all undiminished.
You are, at least by percentage, less human though. There is less human of you than there was before. But you don't feel or act any less human at this point.
Now if you keep going, keep adding, keep removing parts and changing yourself, well, in the Technoshock era, that's a problem.
It's a problem for people now, by the way. It's very jarring to lose parts of yourself or have parts held together with metal bolts. Some people are fine after a brief period, others less so.
And in the Dark Future of rapid, rapid tech, this can lead to a mental disease. It's not a de-humanizing-by-numbers, remember, it is a psychosis brought on by societal change that the sufferer has not adjusted to very well.
And again, it really varies from person to person. But, basically, a cyberleg - as empathic as ever, typically. Even both legs, quite common to see an unchanged empathy response.
Cloned limbs, for example, are also quite common. Personally I find a limb that was cloned from my now destroyed limb weirder than a machine replacement, but that's me. No empathy cost for cloned limbs.