Fair point, but doesn't that also kind of muddy the waters because interfaces also being a regular programming construct? E.g. you might have 50 libraries with

Fair point, but doesn't that also kind of muddy the waters because interfaces also being a regular programming construct? E.g. you might have 50 libraries with 50 interfaces that still go in one very large program, no? And in practice that would be very different from chaining 50 different scripts/simple tools together.