There are still tips and vorticies, just not at these speed/size/power settings. The length of the blade is the biggest issue. These are effectively short blunted tips with a hole in the blade. Whether the improvements would translate to air, with all the associated speed of sound issues, is unclear.
Another old option for eliminating such issues is to put the prop in a case, like a jet ski or most modern military submarines. Or just eliminate the concept of tips and turn the entire case.
For small fish they’re probably about the same but they seem like they’d be superior for larger fish since they wouldn’t be able to get drawn into the middle so you’d have less strikes along the backs like you often see on whales or large sea animals.
Another old option for eliminating such issues is to put the prop in a case, like a jet ski or most modern military submarines. Or just eliminate the concept of tips and turn the entire case.
https://en.wikipedia.org/wiki/Rim-driven_thruster