The fact that electricity was quickly commoditized does not guarantee that AWS will commoditize.

Still, there is a difference of degree. The engineering cost of making one city's electrical grid compatible with the consumers of a different city's grid were much lower (even if one grid was AC and the other DC) than the engineering cost of moving from AWS to a competitor because electricity is not that complicated.

Also, I doubt anyone was referring to electricity as a commodity in the early days before the industry developed standards.