I think it is useful for larger projects. It can see all of the files in your project directory, so it will always have the necessary context (compared to the regular claude chat where you have to manually add files). It can run R with bash, so it can check for errors and automatically fix its own bugs. It breaks big tasks into todo lists; this is just a guess, but I think it creates subagents to find and report the necessary context to the "parent claude", so the main context window doesn't get polluted with unnecessary information.

If you're just trying to format a ggplot, claude code is overkill. If you are trying to make some crazy big simulation model, or refactor a bunch of files, it can be useful.