I’d probably add that for something like nextcloud granted scopes can be an „orthogonal”–for the lack of a better word–subset of requested scopes.

The set of requestable scopes has to be defined by the system itself, not its specific configuration. E.g. „files:manage”, „talk:manage”, „mail:read” are all general capabilities the system offers.

However, as a user I can have a local configuration that adds granularity to the grants I issue. E.g.: „files:manage in specific folders” or „mail:read for specific domains or groups only” are user trust statements that fit into the capability matrix but add an additional and preferably invisible layer of access control.

It’s a fairly rare feature in the wild and is a potential UX pitfall, but it can be useful as an advanced option on the grant page, or as a separate access control for issued grants.