The problem with this is that to produce quality, you actually need iterative feedback from stakeholders and users/user representatives. If you don't show anyone anything until it's "done", you are doing work in a direction that would have been better informed by more feedback.
(Cause another lesson is that people have a lot of trouble giving worthwhile feedback on a verbal/written description of something, they gotta see a thing in front of them).
But I think that's still possible. For example when testing a new idea that just takes some months, it's pointless to show an alpha version where half of the buttons create error messages - even if it solves a much more valuable problem and these errors could be ignored. Instead one should make a presentation of a mockup or a screen recording how a single feature will work. That's much more digestible for everybody and gives far better results if the one watching has anyways only 3 minutes time.
(Cause another lesson is that people have a lot of trouble giving worthwhile feedback on a verbal/written description of something, they gotta see a thing in front of them).