Why are some actions unavailable for federated datasets?

Some actions, like adding sources or processors, are not available for a dataset that uses a federated resource, for example a dataset from the Opendatasoft Data Hub. These actions are either disabled in the back office, as in the grayed-out Add a new source button shown below, or simply do not appear, as with the Processing tab.

This is because a dataset that uses another dataset as a source is not a regular dataset but a "federated" dataset, which is essentially a view of another dataset.

While some customization options are provided, they are limited to simple actions that either filter records or override metadata.