Why is it not "εγώ τρώω τα μπισκότο."? I get that the translation would be "I eat cookies" vs mine which is "I eat the cookies" but I was under the impression that nouns usually have their articles even when they wouldn't in English.
That's true for generic statements when the noun is the subject of the sentence. "(The) cookies are tasty" (=Τα μπισκότα είναι νόστιμα). If the noun functions as the object of the sentence, then the two languages usually follow the same pattern.