In general I would say that, for public functions, whenever you get more than 3 or 4 arguments you should really look into making them all (or at least some of them) a keyword. As @Qqwy mentioned many positional arguments are error prone.
Another, not mentioned yet, but very important use case are boolean arguments. Positional boolean arguments are a horrible API (most of the time), using keywords makes it slightly better since you’re able to name the thing.
Pattern matching on keywords is indeed problematic, but there are ways they can be used cleanly. A solution that I really like and often see in Erlang code, but rarely in Elixir, is reducing over the keyword to build some sanitised state.
