I have mixed feelings on flash fiction. On the one hand - and as the author points out - I think it can be useful as a creative exercise. It’s arguable to say that writing in such a concise manner isn’t something that the majority of writers employ; we so often hear that details - and many - make the picture. (The exclusion to this is perhaps screenwriting where descriptive brevity is honored and actors make the painting truly come to life.)
On the other hand, flash fiction in a way feels like a cop out - like something that counts as writing in an age where character limitations exist. I understand the importance of concision but limiting word counts feels like a limitation on the story’s potential. Make that’s the point?