Software DEVELOPMENT is a lot of design and problem solving. It also usually involves changing requirements and discovering limitations of the tools. I agree that there's a lot of uncertainty in the development process.
Software DELIVERY is what management, customers, and users care about. If a software system does not meet requirements, or if it's so late or over budget that it's a net loss to the customer, it matters little how well-designed it is or what problems were solved.
By predictable and repeatable I mean the entire process. Obviously not every aspect of of the development process can be predicted, nor are projects enough alike to be produced by an assembly line. What management and customers want is a reliable prediction that the system will meet requirements and be finished on schedule and within budget. And they want to believe that a process that can deliver a system this year can do it again.
An architect can reliably predict that a house or an office tower can be made from their plans. A chip designer can predict that a working CPU can be designed and built. An automobile designer can predict that a working car can be made. And these processes are repeatable. Any designer/builder will encounter problems to solve and changing requirements. Failures occur in these realms, too, but not nearly as often as with software projects.
I've heard the argument that software development is different: it's a creative process, the people are idiosyncratic, the problems are unpredictable. I think big-budget movies face the same challenges, but even in that domain there are predictable and repeatable processes that are reasonably good at delivering.
I agree that "Looking for something that can perfectly transform any human requirement into code, in a predictable manner, is just silly." I didn't write anything like that, nor is that what I think anyone means by software development methodologies.