>It's car manufacturing. Everything that could be done by a purpose specific robot arm bolted down to the factory floor is already done by a purpose specific robot arm bolted down to the factory floor.
>What remains unautomated, then?
Stuff that can be done by purpose specific robot arms on wheeled platforms, which is very difficult, but will be much more feasible than a humanoid robot doing anything.
No one ever considers the physics of this situation.
You can't put a robot arm on a wheeled platform without making the platform very heavy otherwise the whole thing will topple over. This gives your entire assembly a mandatory floor space requirement that may be quite large, and severely constrains how much reach you have (see the Handle robot from BD itself).
A platform like the Segway with a self-balancing system can help with this, but since it doesn't have legs it has very little ability to keep the top of the platform steady - all it can do is accelerate around to try and accommodate wobbles, whereas a bipedal robot can simply shuffle it's legs around and keep the top of it's body stable.
It is difficult to build a control system which can do this, but once it's done it's done.
>What remains unautomated, then?
Stuff that can be done by purpose specific robot arms on wheeled platforms, which is very difficult, but will be much more feasible than a humanoid robot doing anything.