OSB is absolutely a fine air barrier assuming <60% humidity at all times. That does not make it a sane choice for sheathing/flooring material given the likelihood of moisture ingress. Every form of seam sealant known to man bites it at some point due to thermal expansion cycles, uv damage, etc. and that's assuming perfect installation of all layers of the moisture control stack. It isn't even a good choice for cabinetry due to it's propensity to devolve into Nature Valley Granola when put in proximity to a sink, dishwasher, or refrigerator (if a cold water line is part of the install).
In theory vapor accumulation is only really problematic in the overhead plenum spaces. In actual practice (setting aside acute water ingress) 100% of the time moisture problems start in the crawl space and then spread to the plenum.
Yes absolutely it is possible to design complex interlocking systems that at least in theory both provide high efficiency sealed construction and control moisture. In practice the complexity of these systems is sufficient that even top-end contractors frequently run into issues that lead to full blown abatement projects. There is also the minor issue of what happens if all of these systems aren't subjected to aggressive inspection regimes and/or a structure goes a significant amount of time unoccupied. The one thing all of these super high-efficiency sealed systems have in common is they quite literally tear themselves apart if neglected or the power gets turned off for any meaningful amount of time.
The statement "If structures don't dry they rot" is absolutely true, but only in the context of traditional lumber products that are comparatively resistant to rot in the first place and are capable of weathering swell/shrink cycles without falling apart. Highly engineered products degrade aggressively just by getting damp in the first place as swelling wood fibers break down bonds with the adhesive that's holding the material together.
I absolutely stand by my original statement that OSB shouldn't be code-compliant and with the exception of shitty flat-pack furniture has no business anywhere in a home.