Most really creative work is. Writers proverbially are loners, so are artists who are actually producing rather than showing off. Even architecture is solo in the design phase, it's also iterative; you come up with ideas, show them to the client, get their feedback, go off revise your ideas, and around again and again until the client is satisfied enough to start building; then the new set of changes start when the client sees it being built and starts making more changes. That's why the architectural and landscape designer I used to work for ONLY worked cost plus.