What is the reason SCCM is used over Intune app management?

Hi, so i'm trying to understand this space better and i'm wondering why a company would decide to run a co-managed setup instead of going fully Intune?

Is there a featureset in SCCM that Intune simply cannot replicate? Or is it organisational inertia and the friction a migration would cause?

Appreciate any light shedding and thanks!