StatefulSet volumeClaimTemplates cannot be updated after creation ... but WHY is this?

StatefulSet volumeClaimTemplates cannot be updated after creation - Kubernetes forbids this.

This is quite an irritation as it prevents, for example, increasing the size of PVCs created for future scale-ups.

There are various related GitHub issues which have been hanging around for years and repeatedly being marked stale/rotten, and revived.

My question here is related, but not the same:

Does anyone know why changes to this field need to be forbidden?

I understand applying the changes to existing PVs is hard… but why is it necessary to prevent updates to the template that will be used to create future PVCs/PVs?