I think AGI can change the world once it gets way beyond human level both in terms of types of beyond-human "senses" and pattern matching/prediction (i.e. intelligence), but we are nowhere near that yet.
On their current trajectory LLMs are just expert systems that will let certain types of simple job be automated. A potential productivity amplifier similar to having a personal assistant that you can assign tasks too. Handy (more so for people doing desk-bound jobs than others), but not a game changer.
An AGI far beyond human capability could certainly accelerate scientific advance and let us understand the world (e.g. how to combat climate change, how to address international conflicts, how to handle pandemics) so be very beneficial, but what that would feel like to us is hard to guess. We get used to slowly introduced (or even not so slowly) changes very quickly and just accept them, even though today's tech would look like science fiction 100 years ago.
What would certainly be a game changer, and presumably will eventually come (maybe only in hundreds of years?) would be if humans eventually relinquish control of government, industry, etc to AGIs. Maybe our egos will cause us to keep pretending we're in control - we're the ones asking the oracle, we could pull the plug anytime (we'll tell ourselves) etc, but it'll be a different world if all the decisions are nonetheless coming from something WAY more intelligent than ourselves.