To begin with, systems that don't tell people to use elmer's glue to keep the cheese from sliding off the pizza, displaying a fundamental lack of understanding of.. everything. At minimum it needs to be able to reliably solve hard, unique, but well-defined problems like a group of the most cohesive intelligent people could. It's certainly not AGI until it can do a better job than the most experienced, talented, and intelligent knowledge workers out there.
Every major advancement (which LLMs certainly are) has caused some disruption in the fields it affected, but that isn't useful criteria that can differentiate between "crude but useful tool" from "AGI".
I mean "hard" in the sense that it can reliably replace the best software developers, civil engineers, lawyers, diagnosticians. Not just in economic sense, but by reliably matching the quality of their work 100% of the time.
It should be capable of methodically and reliably arriving at correct answers without expert intervention. It shouldn't be the case that some people claim that they don't know how to code and the LLM generated an entire project for them, while I can confidently claim that LLMs fall flat on their face almost every time I try to use them for more delicate business logic.