Yes, I know: analysis like this really isn't very necessary for what is essentially a shonen. The Dragon Ball franchise utilizes an incredibly simplistic narrative structure. This is still true for Dragon Ball Super, and Dragon Ball Super: Broly. But it's still fun to take a look at in detail, especially at the things we might otherwise miss during the spectacle of it all.
A few quick notes to think about before going in. Mainly it's that Akira Toriyama, the creator of Dragon Ball, has a very lax way of writing his stories. In essence, he writes stories specifically for the chapter, not necessarily for the arc as a whole. This in turn results in multiple retcons across the story's entirety.
The official excuse is that he is forgetful, which may or may not be true. I believe that the real reason is that he just doesn't care - he is more invested in his characters' future than he is in their past. While this does suck from a plot cohesiveness standpoint, it has its upsides as well. Because the writing is lackadaisical, it means we should enjoy it similarly. Which is a cheeky thing to say, when a good portion of the Dragon Ball fandom takes it far too seriously.
For example, there are too many people out there that are obsessed with how powerful the characters are, and must know what their capabilities are in a numerical sense. Of course, Toriyama is the cause for this technical obsession with 'Battle Power'. His initial usage of it is designed to heighten tension. It's a cheap shot, but very very effective. He has since come to the realization that the device he once employed will become its own narrative barrier. Though he does his best to distance himself from the Battle Power thing, the damage is already done. There are far too many fans who crave it at this point.
In short, Dragon Ball has two sets of fans. The first set of fans typically love the story's quirky, weird, colorful characters and their arcs. The second are also obsessed with the characters, albeit more about how well they fight, how strong they are, and how unstoppable they can become. There's nothing wrong with either set, but you can already see the fundamental differences that guides almost all creative decisions.
For the most part, Toriyama caters to his first set of fans through the manga, which is now drawn and developed by Toyotaro. As as aside, and to help lend credence to my viewpoint, Toyotaro is arguably Toriyama's #1 fan. What they do with the manga is stunning.
This must mean that the second type are catered to via other means - specifically the anime. On top of that, the movies in the Dragon Ball Z era take it up a notch. Most of the type two fans love the films, especially classic Broly. This is especially true of DBS:Broly. The only difference is that this new Broly has the official stamp of approval from Toriyama himself.
There's an interesting technical facet to any fandom, and that's determining what parts of what story is canon, and which are not. In the case of the Dragon Ball franchise, only stories that Toriyama himself has written are counted as canon. This has put the entire fandom into overdrive. Although this movie is clearly made to be serious fan service, there are still parts of it that the first type of fan can enjoy. For example, the classic renditions of Broly represent him as just a mindless, all-powerful animal. The new Broly has much more pathos, and thus far more narrative potential.
Stay tuned as I delve a little deeper into the characters next week!