From my perspective, literally being used for emphasis does not actually change its meaning, it’s simply hyperbole.
If you complain that you’ve been “waiting for hours”, even though it’s been 45 minutes, that doesn’t change the meaning of “hours”, you’re just exaggerating.
Hyperbole is a stylistic element; style is a completely different level of language than grammar/spelling/semantics (word meanings). As another example of style, ending a sentence with a preposition is grammatically correct but stylistically not recommended.