Almost nobody cares
Exchange+AD is now so complex to manage that paying for a O365 subscription is cheaper than setting up the infrastructure and the properly trained and experience resources to keep it running. Outside really enormous setups. That's why business move in droves to cloud subscriptions.
Sharepoint is/was the LotusNotes replacement that, like Notes, never went past the miriad of abandoned prototype apps/sites that no one used but filled the corporate niche's manager need of feeling important by having its own "sites".
Neither of those are relevant now.
Biting the hand that feeds IT
