But past a certain scale special purpose machines will always be more cost effective.
But it's also not very accurate on that count: we are actually very strong compared to mechanical systems of a similar size, weight and energy structure.
- plant new plants (hold plant in pot, remove plant from pot, shake excess soil, dig hole using trowel, place plant in hole, pat down earth, water plant using watering can)
- dig up weeds (using e.g. a hoe, fingers)
- set up a trellis (attach trellis to wall using drilled-in screws; wrap vines around trellis)
- water plants with hose (unwrap hose, turn on tap, spray plants)
etc.
What form factor will beat humans at all these tasks?
But
(a) Those things look like they need a wide berth to move around and flat terrain
(b) Those end effectors are far from universal. The payload weight seems so low that it even dropped an empty box at https://www.youtube.com/watch?v=3FIXjy2GWTg&t=150s
Still plenty of value from special purpose and from remote control, but that's the timeline for solving both at the same time.
* even with the compute being external, the global electricity supply is presently a few hundred watts/capita and already being used for all the other things we want electricity for, hence all current anger about data centers making electricity too expensive, but renewables could tilt this to 8 billion robots with 1kW compute each in as little as 10 years if we brush aside all the decarbonisation efforts and keep burning petrol in cars and gas in stoves etc., otherwise more like 15 years for that.
Well, yes, you can use a humanoid robot for that, but there are far simpler robotic solutions. There are lots of systems for handling standardized totes.