!! Major spoilers ahead. Proceed with maximum caution!!
There is a large probability that the Infinity Castle Arc is the end of the anime.
After all, the whole plot is about slaying demons, and Kibutsuji Muzan is the ultimate demon. In the Infinity Castle Arc, Muzan was defeated and ultimately killed. Muzan's death meant the annihilation of the whole demon race, with the exception of Yushiro. Thus, we can safely assume that since the main goal is accomplished, the series will end. Additionally, sadly, during the fight with Muzan and/or the rest of the Upper Rank Demon Blood Moons, five Hashira, namely Obanai Iguro, Shinobu Kocho, Mitsuri Kanroji, Muichiro Tokito, and Gyomei Himejima all died. With nearly all the Hashira and a large number of the major supporting characters gone, the story plot would've had a hard time building up another cast of characters. Finally, the manga ends with the Infinity Castle Arc, so it is quite plausible that the anime will end here as well, given that Ufotable does not have a tendency to extend to story even further than the manga.