I don’t see it as the same type of thing at all. I’ve trialled Gingko in its various incarnations over a number of years (7 iirc), so I’m fairly familiar with it. It suits some people very well and appears to enhance their productivity. It’s visual. But it’s not the same thing as Longform.
afaics, Longform adds a sequential structure to scenes (it would be enhanced if chapters and sections were added) like the file pane in traditional outliners such as Scrivener, Atomic Scribbler etc.
(fwiw, I think the kanban plugin can stand in for some of the corkboard functions.)
Another very visual option would be to write scenes in Google Keep using extensions to compile into Docs; can be reasonably powerful.
Gingko combines this style of visual appearance with a hierarchical/sequential structure. So I see it in the same use space, but being an entirely different concept, and likely appealing to different users.