I see this view a lot on HN, but this kind of wish for great new development can be unrealistic simple because there are no more low hanging fruit for these ver

I see this view a lot on HN, but this kind of wish for great new development can be unrealistic simple because there are no more low hanging fruit for these very physical processes. It could easily be the case that RO is going to see only marginal improvements for the next decade or two (except perhaps some test membranes that are too expensive), and modern RO already uses energy recovery in the process.