To use Lodash, a developer needs to know what is available there in the first place. You're taking it for granted, but everyone, you included, had to study its documentation and memorize which functions were there, even if it was only to "look it up" later.
Someone like you could have said a few years ago about Lodash: "why do I need this stupid library, I will just use for loops everywhere, like I learned in college. They get the job done and my role is to provide value, not to care about libraries or code reusability".
With this website, it's the same thing: it's there to teach you which things in Lodash aren't needed anymore and which are. Then it is up to the developer to use what's best. Not everything in the internet is prescriptive.
Blind dogmatism shouldn't have a place in our profession.