>>48756188It's not just about being the same as before. Consistency implies that the series retains its level of quality relative to the advancements of technology, without making too many changes. Dragon Quest is consistent because it retains the same visual and game design sensibilities that go all the way back to the original game, but it also updates all the stuff that needs updating, such as important QoL changes, graphics, technology in general, and scope.
Stagnation is when the series remains the same regardless of advances that happen around it. For the standards of late 90s Game Boy development, Pokemon games were mighty impressive. But standards evolved, while Pokemon didn't. BDSP is painfully small and boring compared other RPGs of our time. Take Atelier for example - those games are very low budget, they're released annually, but they are fucking miles ahead of anything GameFreak does.