Serenity (2005) is a lowish budget space western. It occupies that challenging place between low budget and big budget. The script really demands better special effects, but the budget didn’t cover it. (Apparently, the special effects budget was lower than the TV series Firefly, which Serenity was based on.) With a budget of $39 million it took $40.4 million.
I’m not an expert on film financing but it probably needed more than that to break even, taking into account paying back interest on loans, and promoting the finished product. Annihilation (2018), for example, might have faced a similar conundrum. It had a budget of $40 - 55 million, and took $43.1 at the box office. While Ex Machina had a more limited $15 million budget and took $36.9 million. A limited scope can mean that the limited special effects budget is used to greater overall effect. Likewise, if Serenity had gone more in the same direction and limited its scope, it might have made a better film, even if it would have had a different story.
Almost any film with a hobbled special effects budget is going to struggle to be taken seriously. And then, as a knock on effect, it probably won’t get the promotion it deserves either. Imagine Kubrick’s 2001: A Space Odyssey with zilch special effects budget, it wouldn’t be the same film.
With that caveat, and the fact that the plot is underwhelming, the banter between the crew is probably the biggest strength of Serenity, and probably why it has cult status with its fans.