It's rather a non sequitur, as no one ever said immutability was enough.
You also need design, rigor, error handling, common sense, some caffeine, testing, and fast builds. All together... that's enough!
You also need design, rigor, error handling, common sense, some caffeine, testing, and fast builds. All together... that's enough!
Interestingly, immutability and fast builds are often closely related, because immutability (in build systems) can be used to ensure referential transparency, which makes it trivial to implement caching of intermediate build artifacts.