Most of what I'd say is in the HULK link MisterFrancis posted.
A lot of film schools teach certain structures either as a kind of shorthand or just to give students an overview of comparative literature, because some of this stuff is interesting but fairly academic. Hero's Journey, for instance, is not a story structure at all but rather a (debatably very flawed) ethnographic comparison of major cultural mythologies by Joseph Campbell, who wasn't a writer and had absolutely no intention for the model to be used by writers. It's about as useful to storytelling as observing that Red Riding Hood and Snow White both have female leads in similar roles. It's intentionally broad in order for its thesis to work.
Some profs and students end up as devotees to these shorthands and, rather than reading them as comparative analyses they try to hammer every story to fit. Novels as a form don't work like movies do. For starters, novels are long-contact media. You don't have to worry about the need for an audience to use the bathroom because, chances are, your audience is reading your book while going to the bathroom.
Most novelists would do better to read The Iliad and other epic poetry, because the forms share, IMO, a tendency towards episodic scene-based storytelling as well as a need to summarize and occasionally repeat/recontextualize events that happened awhile back in the telling. More recent TV, especially that written for streaming/binge-watching format, shares a lot of those tropes, too.
If you're genuinely curious about this kind of stuff,
do the reading. Think critically about it. And the second the theory stops you from actually writing or writing what feels right is the second you've taken it too far. I love this stuff, I've read a lot of this stuff, but I can't say I think about it at all when I'm writing.
I suspect if you consider the three acts simply Beginning (where you're laying out the problem for the characters), Middle (where they're working it through) and End (where it, um, ends), most things have a three-act structure by necessity. Leaving out any of them would lead to a very frustrating story, and only the most avant-garde of writers could make a success of it. (Heaven help us when the writer decides that the End is dispensable, and leaves us hanging at the conclusion of the Middle. "It's ambiguous and multi-layered!" No, it's unfinished, like ungrouted tile.)
I broadly agree with this, but what also ends up happening is that the Middle ends up baggy either because the writer is trying to insert all the various unnecessary "steps" of the Hero's Journey or because the writer is trying to create a "Middle" or a second act without actually needing to, resulting in a lot of unmotivated, directionless action or a sub-plot simply for a sub-plot's sake. It really comes back, IMO, to the needs of one's specific characters and plot. The drama, basically. The best read for that is probably Aristotle, but the real point of Hero's Journey is that so much of this stuff is ingrained in us just by reading that I really think the best way to go about learning story structure is simply to read a lot of books.