I made an account specifically to address some of the critiques I've read. For context, I went into the movie blindly, knowing nothing about it. I came out of the movie thinking it was the best I've seen in a while, and saw it again the next day. Naturally, I took to the internet to see how it'd been reviewed and I was surprised to see some critiques, but I was curious as to what other people caught that I didn't, so I read through them. I kept seeing the same ones over and over, and that led me to writing this review directed toward them.
1. Portrayal of the rich family and poor family: I've read critiques about how the movie didn't do a good job making the audience sympathize with the poor family, leading the viewers to view them as criminals/con-artists. I've also read critiques on how the movie didn't do a good job villainizing the rich family and ~SPOILER~ weren't convinced by Mr. Kim killing Mr. Park at the end, feeling like it wasn't deserved. To me, that was the point. That is what escalated the movie to another level. Any movie can portray the poor as innocent/down on their luck and the rich being corrupt and cruel. It makes it easy for the viewer to pick and root for the hero. I think those negative reviews is just a matter of having to sit with that discomfort of not having a clear-cut protagonist.
What you have instead, is something more multi-dimensional;you feel sympathy, but not too much for the poor family as you also see the villainous side; how they got their jobs and pushing others out of a job to do so, refusing to help the old housekeeper's husband in the basement, etc.
At the same time, you don't feel like the rich family is overly cruel. They are ignorant and they are naive, but they are certainly not villains; Mr. Park holding saying it's not a test but testing Mr. Kim, his phrase about "not crossing the line", and the mom talking about the rain in a positive way, ignorant to others who have suffered because of that same storm. These subtleties were executed excellently. For me, it was a commentary on the system as a whole that creates these economic divides, and the people in these systems may not be necessarily perfectly good or completely evil. If they had done it in the latter way (good v. evil), it would read like any other plot of any book or movie.
2. The murder of Mr. Park: In the same line, this critique came from a common thread of people not being convinced that he either deserved to die or that Mr. Kim would do this. I was completely convinced. Mr. Kim had been dealing with the "not crossing the line", and the smell of the poor thing that Mr. Park did just before Mr. Kim killed him. Mr. Kim had also just lost his entire place of living and still went to work the next day for a family who was completely ignorant to that. Right before the scene, Park reminded Kim not to cross the line, and Kim listened to the wife talk about the blessing that was this rain, while he stayed up all night in a shelter. In the moment that Mr. Kim murdered him, he saw a man going after his wife, he saw what looked like his dead son, and he saw his daughter dying before his eyes. He also saw a man prioritizing his own son (which we get) and turn up his nose in disgust at the dead man that smelled like Mr. Kim in front of him.
3. The ability of the poor family to con the rich family: Many seemed to feel unconvinced at this. I actually felt that it was an indicator of how being smart/cunning doesn't lead to wealth and prosperity. Being poor in their environment means they need to be strategic about certain things, just different things than a rich family would, and that would require skill. If anything, skills essential for survival. To me, this spoke to the lack of opportunity and when an opportunity presented itself, they excelled at accomplishing what they needed to. Based on some of the dialogue in the movie (cake business going under), it shows how sometimes luck is needed, and ability is not enough to become wealthy.
4. The idea that this was a movie against the rich: I didn't get that at all. The opposite, really (goes back to my first point). And with that, I want to end with the idea that not every movie needs to have a clear winner/loser, bad guy/good guy. This one doesn't; it has many layers, and it leaves the viewer thinking about it for time to come.
Everything else I loved about it (cinematography especially) has already been covered in many reviews.