You could also build an AGI to run on a digital CPU but interact with a simulation that used analog coprocessors (which is a thing these days https://www.youtube.com/watch?v=GVsUOuSjvcg).
You can also include quantum coprocessors (which already exist in their infancy) for various things (probably only useful for quantum simulations at this point though).
Also considering recent ML work, an AGI is more likely going to run on something similar to a GPU than a CPU.
The way I see it is that humans are the stupidest you can be and still create a society. Like a nuclear reaction, you need average human to add a tiny bit of structure on average and it works, any less than that and society is impossible, any more than that and society forms extremely quickly, so fast that evolution has no time to work.
If, despite that, you're trying to simulate an analog entity with an analog computer, or build any analog AGI, the question arises whether it's possible to build one any simpler or faster than existing biological computers, e.g. humans. If no, then why bother?