Why do you think we need general AIs to replace human labour? I'm struggling to find any cost-intensive labour that would require anything beyond a small group

Why do you think we need general AIs to replace human labour? I'm struggling to find any cost-intensive labour that would require anything beyond a small group of specialist AIs to replace human labourers. Also, these discussions tend to assume that we (by which I mean those making these decisions) want to replace every profession with AIs. We don't. Even if we fully automate certain forms of labour, we still want human oversight, if only so we have someone to blame in case something goes wrong.