Shrinks almost always struggle on unit economics. You’re carrying wings, tails, engines, landing gear, and structure sized for a much larger aircraft, so CASM tends to go the wrong way rather than improve. That’s why most successful families grow up, not down.Once you start meaningfully re-engineering things like fuel volume, wing sizing, control surfaces, and weights to make a shrink work properly, you’re no longer doing a derivative, you’re effectively designing a new aircraft, requiring recertification, and potentially lose the common type rating. At that point it’s hard to justify versus a clean-sheet design optimized from the outset for the 80-100 seat, ~1,000 nm mission.