Dense granular flows down inclines remain challenging to understand, but recent advancements in techniques and approaches have brought the field closer to achieving ab initio predictions with practical relevance. The difficulties arise from three main reasons: the limited extent of regions with significant agitation, the complexity of flows over bumpy boundaries and erodible bases, and the need to accurately model microscopic interactions at grain contacts. Recent studies have made progress in understanding these issues, such as predicting correlation lengths in dense gas kinetic theory and advancing theories of particle segregation. An inertial number approach, inspired by observations in granular systems, has been successful in modeling dense flows over bumpy boundaries but faces limitations in accelerating flows and flows down flat walls. Stability analyses of theoretical solutions could provide valuable insights into these regimes.Dense granular flows down inclines remain challenging to understand, but recent advancements in techniques and approaches have brought the field closer to achieving ab initio predictions with practical relevance. The difficulties arise from three main reasons: the limited extent of regions with significant agitation, the complexity of flows over bumpy boundaries and erodible bases, and the need to accurately model microscopic interactions at grain contacts. Recent studies have made progress in understanding these issues, such as predicting correlation lengths in dense gas kinetic theory and advancing theories of particle segregation. An inertial number approach, inspired by observations in granular systems, has been successful in modeling dense flows over bumpy boundaries but faces limitations in accelerating flows and flows down flat walls. Stability analyses of theoretical solutions could provide valuable insights into these regimes.