The idea of an architect working anonymously on a project is intriguing, but far from a parallel to Banksy.
The first difference being Banksy isn’t anonymous, he’s pseudonymous. The distinction is wanting some level of identifiability. He doesn’t want to be completely obscure because of his message.
Second, his medium is highly visible i.e., public spaces, street art (illegal) with a political or social message. That’s why he’s prolific and why his art matters.
Using an anonymous architect to build a high end club with a high end private membership for a well off client does start an interesting golf conversation about how we currently critique golf architecture, but it’s far from anything Banksy is doing.
To answer the original post, the Banksy of golf might manifest itself as a rogue golf architect or golf group “installing” small, pop-up forms of golf in urban areas, vacant lots, abandoned lots, etc. Creating a space for golf that’s not encumbered by yardage, acreage, par, using golf clubs, etc. Make it sort of a Ship of Theseus for golf. How many of the traditional elements of golf can you remove while still making it recognizable as golf? Maybe a developer wipes it out after a day, maybe it exists in a vacant lot for years or transforms after it’s initially built.