The package might not ever be executed on the user's machine. Depending on your setup, it might only be ran on a server, where the data that can be exfiltrated is completely different.
Sure but like.. come on. Is that really a defense? Most packages are run on devs machines. And it's not like "Oh it's just running on my production server, what could go wrong there" is any better.
Why you are downloading code if you're not even using it to run tests ?
And if you run tests in CI/CD, or in a container, why you are downloading code locally ? Only thing that comes to mind is code completion but surely most people at least run unit tests locally before pushing the code out ?