I glanced at that and it doesn't seem very good. It mentions AGI fifteen times but doesn't say how it defines it. It hints that LLMs don't count because they don't do original reasoning but doesn't give much argument why different algorithms can't do that.
I read it too and it seems like the problem is precisely that nobody has a precise definition of what AGI will be. A system that is always right ? If so impossible. A system that is just like humans ? Humans are sometimes right and sometimes wrong so how do you manage it when it is a machine with zero consciousness? At least the article correctly explain why we can't build AGI with LLMs only.
I think people have personal definitions but they differ so it can be hard to know what you are talking about. For me I have it as able to do all the intellectual stuff that humans do including making scientific discoveries, designing new computers and so forth.
AGI doesn't really specify a level, like Deepmind's general video game player was artificial and general but most people think human level or better with AGI.