That's exactly why it would be more scalable as a court decision. A law can never encompass every possible dark pattern, while a new court decision can be added every time somebody discover something bad, and sue.

Additionally, court decisions will be more efficient, since once a pattern is found fraudulent, it is not only banned, but there is also a whole case of discussion to refer to. With a specific law like this, with no prior cases, we aren't really much further than we already were.