The first Darksiders game came out just before the third God of War game and at that time it was something new from Vigil. Years later, we have Fury with her whips and the combat which we have seen can be compared to Kratos and his chains. While God of War is a AAA game with a huge budget and an animation team the size of the total team working on Darksiders 3, the devs believe that they might have a shot.
While Fury's weapon of choice might be similar to that of Kratos in terms of mechanics, these are two very different games. While God of War presents a graphically real world, the Darksiders art style is different and can be called a bit cartoonish. The devs talked (translation) about the matter and the following is what they had to say in this regard:
The term "AAA game" is information that a huge number of specialists worked on a given title for several years, and astronomical amounts were spent on the marketing campaign. However, for others there is still a place on the market, you can still achieve success if you have a decent product offering interesting ideas and experiences. If something is good for you, if it somehow appeals to you, you will choose it anyway, without looking if it is "AAA game" or not.
Source: https://segmentnext.com/2018/07/17/darksiders-3-compete-with-god-of-war/