Water generation (via desalination) suffers from a major distribution constraint (much worse than power) - water can only be moved where there are existing pipelines / aqueducts and it requires lengthy regulatory approvals.
Overcoming the distribution challenge requires a new water purchase model that allows the value of water to be moved separate from the physical molecules. But the model has already been invented - power purchase agreements (PPA's) have been used for decades to buy & sell power (electricity) and power credits, separately.
As soon as the industry recognizes that the same model can be applied to water, it will solve scarcity - buying water credits provides the financing that water generation projects require and local municipalities will benefit greatly from the additional physical water that is added to the overall supply. This will ultimately create abundance and drive the cost of water down.