Kivas are nice and all, but they can't pick and they definitely can't stow. They could probably move pallets, but couldn't palletize, and having them run around the facilities at the necessary speed dragging a train of pallets would be a safety hazard.
They are really good at reading QR codes and turning at 90 degree angles, though.
There are places in India where they pay 100 men pennies to dig a trench. Sure, they could buy a machine so 1 person could do the work of 100, but if the machine costs 100k and the guy who is trained to operate it makes 10 an hour, the payoff time is too long to justify. If the guys digging the trench demand 5 an hour, the barrier to the investment goes down significantly.
This is why, if a 15 dollar minimum wage is passed nation wide, you will never order from a person at McDonald's again... and any niche restaurant that does use people will cost significantly more. A large business like McDonalds benefits from this because they can absorb the cost. A small business can't, so big corporation's have less competition and can make even larger profits because they have less downward pressure on their prices.
With enough money, they could probably reduce the amount of warehouse workers needed.
Other facility jobs, like picking and stowing, run up against vision and fine motor skill problems that turn out to be really difficult for AI and robotics to solve. They'll be automated eventually, but I don't think it will be soon. I might be wrong, though.
https://www.reuters.com/article/us-singapore-robots-ikea/fla...