I think Big Structure (3 act, 4 act, 8 act per Gulino) is a kind of overlay that fits on top of a story. It has the value of making the story feel familiar to a reader / viewer, and this is essential.

But superimposing Big Structure onto a bad story results only in a familiar bad story.

The story has to be well crafted (dialogue, character, theme, etc.). Otherwise Big Structure goes to waste.

But even a well-crafted script with an appropriate Big Structure may not make a compelling movie (though such a movie will probably be more engaging than if the script lacked those elements).

Besides mastering Structure and craft, writers have to use (or develop) their intuition, which usually means intuiting how a significant number of viewers would react to a movie based on their script.