Speaking of automation, you might be interested in this article at Supply Chain from a few years back on the top 10 automated warehouses. Most of the automated warehouses in their list aren’t.
The reality is that there aren’t a lot of fully automated warehouses.
I don’t have the figures in front of me to support the claim but my guess is that the cost of land is driving the move to warehouse automation as much as employee compensation if not more so. I know of a lot of very large warehouses with just one picker already.
While Amazon doesn’t use a high degree of automation, their ‘chaotic storage’ system is pretty innovative and efficient (for its purposes.) I’ve had the opportunity to learn about their processes a bit because my husband has overseen the construction of several of their distribution centers- quite interesting!