Observations find that the mix of galaxy morphologies—disks, spheroidals, and irregulars—evolves more slowly at late times than many ΛCDM-based hierarchical models predicted, with thin disks remaining surprisingly common and a substantial population of settled disks already in place at high redshift (z ? 1–2), suggesting a “stall” or slowdown in morphological transformation (Avila-Reese 2007; Aumer et al. 2013). Standard ΛCDM simulations often overproduce bulge-dominated systems and struggle to maintain fragile thin disks through the expected merger rate, implying that additional fine-tuned feedback, environmental, or merger-suppression mechanisms are needed to reconcile the predicted morphological evolution with the observed, more gradual changes (Avila-Reese 2007; Aumer et al. 2013).