A model given "write a cold email to a VP Sales" produces the same email everyone else gets. A model given the ICP, the persona, the trigger, three real customer quotes and a strict set of rules produces a first line a good SDR would be proud of, for a thousand accounts.
The skill has moved from writing to specifying: the research the model gets, the rules it follows, the examples it copies, and the check that reads the output before it ships. The club's library is largely this: skills that encode how good copy is made.