This isn't true. You can feed the energy gained from dehumidification back into the humidification phase. Last I checked this was able to make the two about equal as far as energy inputs required, but good engineering could perhaps get it better. Reverse osmosis has energy requirements that seem harder to reduce, but of course advances can happen anywhere anytime.

Feel free to fact check the above: I'm not an expert and may have been reading marketing materials that hide something important.