I have yet to read any scientific research that states that stacked leaves are an issue in and of itself. Sure, stacked leaves imply that the plant isn’t resorbing its outer leaves in order to grow new leaves, but that isn’t inherently an issue (to my knowledge at least; happy to read any published papers that suggest otherwise). Sure, stacked leaves imply that the plant is getting that water elsewhere to grow those new leaves, but again, that isn’t inherently an issue. The issue that people are worried about is that this plant is overwatered. Yes, stacked leaves implies that the plant might become overwatered, but stacked leaves does not mean that the plant IS overwatered.