I don't know if you comment was sarcasm. If not, how does your methodology specifies and proves that your Powerpoint replacement will draw rectangles with the fashionable gradients of the year you release it. If gradients won't have fallen out of fashion again by then. And that's only a silly example. Programs like that have a huge number of features. I am ready to bet that some of them have been designed and informally approved in front of a coffee machine 20+ years ago.

However yes, anything formal can help and if AIs can hide it from ourselves (we won't be able to follow it) and make it their internal design language chances are that it's going to be really used.