a future were everything egregiously floats, even when it makes little sense or is unnecessary to do so.
Writing a future can be hard, go to far and the setting loses relevance, but go to close and the future aspects become near moot. Thus, writers often use levitation as a visual shorthand. Perhaps borne from the idea of Flying Cars, a Floating Future is a place were everything, cars, trains Anchors floats.
ExamplesIn the Jet Sons, things as simple as plates, and tables float. Futurama spoofs this sci fi trope, billboards, signs, underpants etc all float.