There's a big family of risks here.
The simplest is pretty easy to articulate and weigh.
If you can make a $5,000 GPU into something that is like an 80IQ human overall, but with savant-like capabilities in accessing math, databases, and the accumulated knowledge of the internet, and that can work 24/7 without distraction... it will straight-out replace the majority of the knowledge workforce within a couple of years.
The dawn of industrialism and later the information age were extremely disruptive, but they were at least limited by our capacity to make machines or programs for specific tasks and took decades to ramp up. An AGI will not be limited by this; ordinary human instructions will suffice. Uptake will be millions of units per year replacing tens of millions of humans. Workers will not be able to adapt.
Further, most written communication will no longer be written by humans; it'll be "code" between AI agents masquerading as human correspondence, etc. The set of profound negative consequences is enormous; relatively cheap AGI is a fast-traveling shock that we've not seen the likes of before.
For instance, I'm a schoolteacher these days. I'm already watching kids becoming completely demoralized about writing; as far as they can tell, ChatGPT does it better than they ever could (this is still false, but a 12 year old can't tell the difference)-- so why bother to learn? If fairly-stupid AI has this effect, what will AGI do?
And this is assuming that the AGI itself stays fairly dumb and doesn't do anything malicious-- deliberately or accidentally. Will bad actors have their capabilities significantly magnified? If it acts with agency against us, that's even worse. If it exponentially grows in capability, what then?