And unfortunately, they are also indiscriminate predators that exist at the bottom of the food chain. As such, many things will eat them as their favorite food (basically a floating meat bag, with no bones, that can’t swim away), while simultaneously they may eat a large variety of species. This is similar to cephalopods like squids, cuttlefish, and octopus.
So while it is about as clear-cut “it will not work” more so than any other marine species... it’s up to you if you want to try and pioneer a new field. But you may be working against yourself. I’d be curious if anybody that has done it, like those people you’ve mentioned, which species of jelly they have, and how long it survived.
It would be much easier to design a reef tank with sea horses or pipefish. Which would still be relatively unique and beautiful! My favorite would be the Dragon Faced pipefish