Yes, I know that. However, they don't need to be exhaustive. They are very effective at uncovering any bugs using a statistical approach at even very reasonable

Yes, I know that. However, they don't need to be exhaustive. They are very effective at uncovering any bugs using a statistical approach at even very reasonable levels of iteration. And nothing precludes you from running them 24/7 in the cloud. I wouldn't say using a "unit test" is ever really a viable option for me. Property-based tests subsume unit tests.