I do not believe that we can design a system that will withstand waves and wind from tropical monsoons or even most tropical storms or cyclones in the pacific. I can't speak for other oceans or areas of the world, but I believe that this design requirement will probably make it a non starter.

It's at pilot stage in various places. Japan is leading on this, as they did in floating voltaics generally.

Places with offshore wind are also looking at it as a way to share cables.