Yep, validation is key. The smartest thing I've heard on this, which has reoriented how I think about this is that the objective function of a piece of software is now more important to get right than the implementation.
Turns out what was being rewarded all along is "the code looks all right" and "it looks like it works".
> the objective function of a piece of software is now more important to get right than the implementation
That has always been the case. That is why weeks or even months of programming and other project busy work could replace a couple of days of time getting properly fleshed out requirements down.