What advantage is there to having genders for nouns?
There are a lot of nouns in any language and it's hard to keep track of them all so most languages find ways to lump them into groups...
Grammatical gender is just one way of doing that, of dividing the large group of nouns into smaller categories (and activity the human brain seems to need).
Technically it's not about gender at all but was originally about phonetic form of the word (with gender being used as a mnemonic).
English has lost the original form of gender but has sort of regained a gender-like distinction between count and non-count nouns. Like any gender system it's party semantically motivated and partly lexical (that is, arbitrary) this is especially clear with 'furniture' which might more logically be thought of as a plural but firmly in the non-count category.
paper, a paper
tv, a tv
coffee, a coffe
some words that are usually or often plural in other european languages are non-count in English (information, advice etc)
textbooks are mostly not very good at explaining the very important distinction between count and non-count nouns in English and even very advanced learners tend to revert to forms like "I gave her some advices" or "I need furnitures for my new flat"....