It seems like they do the exact same thing, but have different word lists. How can this be ?
Yep, they’re different tools and made by different people. And they’re not the only tools that enumerate files/folders either.
Gobuster, dirsearch, wfuzz, dirb and dirbuster roughly do the same things. They each have their own strengths and weaknesses though. Personally I’m a wfuzz fan and use that 95% of the time.