Earlier quoted context omitted.
Isn't this why new ships are starting to have multiple 360 degree electrical drivers instead of one big propeller? I think they are called iso-pods.
You mean this? https://en.wikipedia.org/wiki/Azipod I think the biggest issue is complexity and resulting unreliability. On a ship that has to be in constant use for decades you want things that are simple and reliable. "The latest design, the Azipod X, incorporates these improvements, with a view to a service interval of five years, and features bearings that can be taken apart and repaired from inside the pod while…
They're quite efficient (although maybe only for lower speeds) and provide extreme maneuverability.