Is the internet is a treasure chest of information a simile, metaphor, irony, or a hyperbole?

Simile and metaphor are quite similar in terms of comparing the characteristics of an entity to another without using the literal sense. However, the difference is that, a simile uses key words such as, 'as' or 'like' when comparing or contrasting. Metaphor is straightforward without any use of these words. Hyperbole is an exaggeration of things while irony is expressing the opposite of what the thought actually means.

From the descriptions given, the statement is best described as a metaphor.