I’d argue that literally isn’t changing definitions. It still means literally. It’s just that the most common usage of ‘literally’ is in a figurative or hyperbolic way. In fact, if the word DID change meaning to mean the opposite version, its usage would become much less meaningful since it’s usage in a figurative way is done to show extreme figurative to the point that it might as well be considered literal, e.g “literally the worst day of my life”