The modern (english) dictionary aims to serve as a list of definitions and meanings of words for someone who requires a list of definitions of words. This means that the explanations and example usages have to be short and simple because the person using it may not have a full command of the language.
The original Websters dictionary, as far as I can tell, serves to document the language for existing native-language users. This lets it be more expressive in the words definition (because you can use more expressive language), with the expectation that the user of the dictionary already has some sort of mastery with the language.
Nicely put. Sums up entire paragraphs worth of information in a single simple sentence that effectively conveys the idea.