I never really write reviews, but I feel like I had to for this one.
Genuinely one of the most boring, horribly written, cringe-worthy shounen stories ever written. This show is on-par with shows like Fairy Tail, writing-wise. The show is extremely simple and predictable, not once was I shocked, sad, happy, angry. I did not feel a single thing watching this show, other than boredom. How many times are we going to have to see your typical young boy suffers tragedy and becomes an epic super fighter story before we get sick of it?
Shallow, undeveloped, stereotypical shounen characters that do not get an ounce of development throughout the entire show. As a friend expertly said, the main trio is just Deku from My Hero Academia split into three, Tanjiro, the kindness, Zenitsu, the cowardice with occasional bravery, and Inosuke, the part that caused Deku to continuously break his arms over and over. This would be fine if any of them actually had any development (getting stronger isn't character development by the way), but they were the same throughout the whole story, not a single ordeal changed any of them. Shounen fans made fun of moe fans for liking cute anime girls during cute things, yet went berserk over Nezuko, a bottom tier anime character with no personality, who barely passes as cute, who essentially, is just a cute anime girl doing cute things. Overall, horrible characters with horrible writing, nothing out of the ordinary for shounen to be honest.
Animation & Art: 10/10
Ufotable is well-known for amazing animation and art, Kimetsu no Yaiba is no exception to this rule, no matter how bad the actual content of the anime may be. Top of the line visuals and fight scenes, amazing CG, clean art, and amazingly done backgrounds/settings. Episode 19 broke the internet, and for damn good reason, it was a genuinely beautiful fight scene. Every good thing about this anime comes right from ufotable, as the actual show accomplishes nothing, which is something to note.
The character voice acting was average. Zenitsu, Inosuke, and about half the characters had cripplingly annoying and bad voice acting, while the rest were pretty average/decent. The sound effects of the swords and the fighting were top tier, and beautifully done. Not much to be said here.
The enjoyment of watching this show is equivalent to the enjoyment one would get chugging a litre of soy sauce. The only enjoyable thing about this show is the animation, and even then, it barely counteracts the atrocious story and writing. Frankly, this show was completely unnecessary, and probably drained some of the funds off of the new Heaven's Feel movie, so I enjoyed it even less, because it is probably lowering the quality of an actually good franchise.
I wish I could give it a lower score, but anything lower than this would be an insult to ufotable's amazing work. I would never recommend this show to anyone, I will always laugh when I see the absurdly high score this show has, and I will consistently avoid Kimetsu fans on the internet, because they are the new My Hero Academia fans.
TL;DR: I would rather be reincarnated as Umaru-chan's Onii-chan that ever watch this anime again.