Just about every aquatic plant will grow better bare root, I can't think of many that don't. Perhaps some of the slower growing, fleshier rooted plants such as golden club, marsh marigold, lysichiton, gunnera, arrow arum which really like a firm grip on very deep soft mud
Question is, is it desireable...
Crayfish, turtles, koi and a host of peckers can have a field day at the more tender succulent varieties. Some aquatic plants have evolved pecker proof roots, others haven't
Some plants growth rates are all too impressive. Yellow flag iris, large waterlilies, lotus, cyperus can hog a fertile pond rather fast. You might want to find a pot big and tough enough to confine them, or start saving up for a crew of labourers packing chainsaws
Some varieties are tetchy about being confined if the soil is too heavy and thick, lotus can fail...
Some varieties really need anchoring, aquatic iris especially, many is the time a light breeze has carried off a pretty plant to merrily emulate the final voyage of the Titanic in Davey Jones' locker.
Tiddly ittybitty hardy (buoyant) waterlilies can drift out of their pot to an uncertain fate if not pegged down adequately
Regards, andy
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