Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021
Use no article with nouns that refer to all of something or something in general
Articles (a, an, the)
Multilingual Writers and ESL Topics
When a noncount noun refers to all of its type or to a concept in general, it is not marked with an article.
In most cases, when you use a count noun to represent a general category, make the noun plural. Do not use unmarked singular count nouns to represent whole categories.
EXCEPTION: In some cases, the can be used with singular count nouns to represent a class or specific category: The Chinese alligator is smaller than the American alligator. See number 6 in 29b.