Let There Be Carnage is an undoubtedly dumb movie, but it is more tonally consistent than the first Venom. I'm not sure that where they've chosen to land on the tone scale really works, mind, but it is consistent throughout, rather than wildly swinging between body-horror and slap-stick like the first film did. Brock and Venom are now a consistent buddy-film double-act, and their arc can be pretty much perfectly painted onto that format without changing anything. To his credit, I think Tom Hardy does a solid job once again, so I never question the fact that he isn't directly interacting with Venom in those scenes (even if the CGI Venom is looking a little odd at times).
However, Hardy is completely upstaged by Woody Harrelson throughout the film. There are some glaring issues with Carnage as a character – chiefly that the film doesn't attempt to explain how he came to be or why he is so intent on killing Venom – but Harrelson's Cletus plays the symbiote relationship perfectly. Could you do a better Carnage? Probably, but I think you'd struggle, and I'll be happy if Harrelson's version is considered the de facto one going forward. Most of all, though, I want to see Harrelson play a serial killer in a darker, more realistic film, because whilst he does ham it up from time to time here (as is only appropriate in a superhero movie with this much attempted self-awareness), when he really leans into the darker side of Cletus it's genuinely a little chilling.
As for the plot, I thought they did a follow-up fairly well. They skirt over the obvious repercussions of the first film, for the most part, and whilst I thought it was a good move to introduce Shriek and have Cletus be more nuanced than simply a man that wants to kill people, she was never really given much character development or back-story, which is a shame. The rest of the cast broadly return, and do so in ways that felt believable. I like that they've dropped the love interest in a way that feels at least a little organic, but I also wouldn't mind them silently leaving those characters behind moving forward, as they did feel a little shoe-horned in just to add some extra tension.
In fact, that is a consistent gripe. The plot is fine, but there are far too many instances of "we need character X to be in location Y" and then they are just magically there, or we get some contrived reason for moving the plot forward. I mean, symbiotes are clearly powerful, but the idea that they can manipulate the internet by sticking some tentacles into a laptop and magically discover the whereabouts of a top-secret government black site for powered people was just weirdly absurd. It definitely felt like they sketched out some rough plot moments, and then spent a frantic day or two coming up with any vaguely plausible tether between two points, and called that a script. They also kept teasing some kind of big reveal about the symbiotes, but whilst the introduction of Carnage should have been the perfect excuse to flesh out the species and background a little, they just... didn't. The result is an enjoyable movie, with some fun action sequences, but it would have benefited from an extra six months in writing incubation to try and flesh out some of the actual logic behind the plot, and I'm still not entirely sold on the whole comedy routine version of Venom.