Your view is missing the forest for the trees. You see individual objects but miss the aggregate whole. You have a hard time conceiving of how exotic computers can be conscious because we are scale chauvinists by design. Our minds engage with the world on certain time and length scales, and so we naturally conceptualize our world based on entities that exist on those scales. But computing is necessarily scale independent. It doesn't matter to the computation if it is running on some 100GHz substrate or .0001Hz. It doesn't matter if its running on a CPU chip the size of a quarter or spread out over the entire planet. Computation is about how information is transformed in semantically meaningful ways. Scale just doesn't matter.

If you were a mind supervening on the behavior of some massive time/space scale computer, how would you know? How could you tell the difference between running on a human making marks with pen and paper and running on a modern CPU? Your experience updates based on information transformations, not based on how fast the fundamental substrate is changing. When your conscious experience changes, that means your current state is substantially different from your prior state and you can recognize this difference. Our human-scale chauvinism gets in the way of properly imagining this. A mind running on a CPU or a large collection of human computers is equally plausible.

A common question people like to ask is "where is the consciousness" in such a system. This is an important question if only because it highlights the futility of such questions. Where is Microsoft Word when it is running on my computer? How can you draw a boundary around a computation when there are a multitude of essential and non-essential parts of the system that work together to construct the relevant causal dynamic. It's just not a well-defined question. There is no one place where Microsoft Word occurs nor is there any one place where consciousness occurs in a system. Is state being properly recorded and correctly leveraged to compute the next state? The consciousness is in this process.

"'where is the consciousness' in such a system": One could ask the same of humans: where is the consciousness? The modern answer is (somewhere) in the brain, and I admit that's likely true. But we have no proof--no evidence, really--that our consciousness is not in some other dimension, and our brains could be receiving different kinds of signals from our souls in that other dimension, like TV sets receive audio and video signals from an old fashioned broadcast TV station.