Getting the water separated out is only one-half the cost battles for desalinization. The other half has been dealing with the brine collected in the process. Yes, getting the first step’s costs down will help (as they will be with more efficient filters from more efficient materials), but in the long run the second problem - dealing with the leftover brine - needs much improvement as well.
Yes but consider what is in that brine from the ocean...many usable and extractable minerals and metals in a concentrated form...economical? Perhaps the researchers will discover.
Eat more pickles?