Hey Zachary, good question. Assuming that PH is the standard of energy efficiency for this present time.
Why build for the far off future if no incentive drives it. I work within a community that monthly house hold expenses are a daily concern. Regular seasonal building maintenance is way down on the have to do list. This creates a unfortunate circle of need. Dry and tight helps keeping run times short but not having to tear down and rebuild has greater long term returns. Economic, social, environmental etc.