People will keep finding some small case or reason why not to call it AGI. And then finally once that last case is knocked down and we have agreement on a definition, we'll realize we crossed that threshold a "long" while back.
And I'm not saying we have AGI now, just that it's now clear to me how this process will play out.
(Where "long" in AI development timeliness probably doesn't mean the same thing "long" meant even in the 2010s.)
Invention preceding understanding is the norm, not the exception. We created fire before understanding chemistry, and we constantly use pharmaceuticals without really understanding how they work. Invention first, then theory comes along to explain and generalize.
For all we know, sentience is a necessary side-effect of semantic processing of any kind, in which case LLMs already have a form of sentience.
So yes, you're right that we don't understand our own sentience. In fact, we understand so little that it could literally be staring us in the face right now and we don't realize it.
Some people claimed that "creativity" (another rather nebulous term) was a uniquely human trait, and machines could perform tasks that require this. But recent generative AI models have started to make people question that position.
Even though it makes so much sense, I never thought about it like this. Inpainting, Object Detection, Rotation, Lighting, Segmentation, Edge Detection, Pose Estimation, Surface Normal, Colorization and much more achieved by a single model.
I believe this and Codi-2(https://codi-2.github.io/) offer a glimpse of the future of Large Multimodal Models.