While Dragon Ball Movies are basically deemed to happen in their own timeline apart from the actual series, as none of them would reasonably fit into the narrative, there has been a constant with the Broly Movies all taking place in a single timeline. When it comes to this Broly, however, they have dropped that premise entirely. This Broly is in no way connected to the previous movies, and honestly, I think that's for the best.
In a lot of ways, the Broly movies were terrible. This Broly character just kind of shows up and starts wrecking things, and the reason behind his anger is Goku crying as a baby annoyed him. He was also so powerful that the combined efforts of all the Z fighters didn't even seem to make him flinch, so the finale of the original Broly movie felt like complete BS, even by the standards of Dragon Ball Z and it's other movies.
The new origin of Broly is a lot less goofy, and the movie actually does a great job at incorporating a lot of elements of what did make Broly so popular and the things about Dragon Ball Z and Dragon Ball Super to make a much better movie. Well, kind of.
There is no getting around this, pretty much every Dragon Ball Z movie is really stupid, and in a lot of ways, the new Broly movie is no different. The plot is basically Frieza just stumbles across a murder hobo and points said murder hobo and his father at Goku and says 'Kill!'. Said Murder Hobo is arguably stronger than even Beerus.
The movie also comes with all the same problems that Dragon Ball Super had in general, specifically how there really is no consistent strength shown to any of the fighters. Vegeta goes into his Super Saiyan God form and, in the end, gets his ass handed to him. Then Goku enters the fight in his base form, and at first, is holding his own until Broly continues to grow stronger. This comes with the implication that Goku in his base form is more powerful than Vegeta as a Super Saijen God, and that premise is just ridiculous.
At the same time, I think this movie knows exactly what it wants to be, and has knowingly thrown all sense out the window. The battle becomes so epic they are fighting inside a current of lava, and eventually punch themselves into another reality as the music in the background has vocals of people changing the names of the characters fighting in an epic fashion.
On the surface, this sounds incredibly stupid, and it is. But there is just a complete lack of shame and passion that everything obviously wrong with this movie just stops mattering. It doesn't even feel right to go into more, like how silly the relationship between Broly and Cheeli (Who is currently in the running for best Dragon Ball Girl) actually is, and how stupid it is she becomes so attached to Broly after so little.
This entire movie is nothing but the fight, and it is glorious. Not even just because of the over the top nature I mentioned before, but the way the animate Broly, Goku, and Vegeta. There is a distinct way that Goku and Vegeta move, their actions really do seem a lot more planned and deliberate. Compare that to Broly who isn't really much of a trained fighter, and his actions look wild and sporadic, and it's something I always took a bit of issue within the main series with how indistinct everyone’s fighting styles started to look after a while.
Then there are so many laughs to be had, like how Frieze ends up fighting with Broly. I don't want to spoil it for those who haven't seen it yet, but it is the funniest bit in the movie. If you are at all a fan of the humor of Dragon Ball Super, you will be in for a treat here as well.
In a lot of ways Dragon Ball Super: Broly is among the worst movies of Dragon Ball with all the flaws of Super paired with an extremely weak plot and set up. At the same time, all of that stops mattering when you witness a glorious fight of shit that borderline doesn't make sense, but is a blast to watch all the same. If you are a fan of the series, it's worth the watch.