Kimetsu no Yaiba is honestly way too good of a anime/manga. Shounen Jump is enjoying a nice era with a series like this and Boku no Hero Academia around, amongst others that I've heard are catching up in quality. I watched the most recent episode of Kimetsu no Yaiba this weekend and found it enjoyable (as I always do). The particular part of the story that the show is currently at is more transitionary, as one arc has just closed and the next is preparing to begin. The characters present in the story as of now also allowed for me to hear a wider array of formality from the characters, which I think is good for listening practice. As is often the case with anime, there's a fair amount of diversity in the speech patterns of the characters to begin with.
Quick plot info dump: this takes place in Japan, demons exist, demons eat people to survive and become stronger, the Demon Slayer Corp formed to fight back against them (currently in the early parts of the Taisho Era, so 1912 or so, which surprised me when that became apparent), the main character, Kamado Tanjiro, wants to turn his little sister, Nezuko, back into a human after the standard tragic catalyst that protagonists must face, plot starts moving.
If you like anime (especially shounen), this is really worth watching. If you like the anime so far, I can strongly recommend reading it (the manga should be ending soon, which is excellent for the anime). It is far more than just a series of fights. There is legitimate character and meaning given to so many of aspects of Kimetsu no Yaiba. Tanjiro serves as an excellent protagonist as well. The anime is extremely loyal to the manga and honestly, due to the quality of the animation studio, UFOTABLE, improves upon the artistic nature of the show thus far.
Also, the intro (Gurenge) and overall sound design (every episode has a really satisfying clip for the beginning) is phenomenal. The singer, LiSA, is rather popular; during the weekend that I spent in Tokyo, I saw advertising for the song and the anime literally everywhere in Akihabara.
Anyway, Kimetsu no Yaiba definitely earns the respect and admiration that it has been receiving (including the spike in popularity from Episode 19).