But if we built a Turing complete, sewer-like system that simulated every neuron in a human brain, it will claim that it is real and conscious for sure. There's no paradox at physical level, intuitively conceptualizing it is the "hard" part.

To your question, the answer is similar. If we remove this limitation of intuition, there doesn't seem to be a real paradox. Both you and a spreadsheet-like copy of you would each claim to be the real you, and from an outside observer's perspective, there is no contradiction.

Also, the emergence of a consciousness like illusion kinda follows from an evolutionary perspective. To survive, a "calculator" brain needs a model of the external world in order to predict how it will evolve and to act in ways that improve survival odds. Once such a model exists, it becomes almost inevitable that it also includes a model of the system itself, since the brain is also part of the world it is modeling and an agent within it. This self-referential loop is likely what we experience as "consciousness" and it becomes central to how we understand and navigate reality.

If we accept this framing, many traditional paradoxes dissolve on their own. The problem stops being "hard" in substance and becomes hard only in terms of imagination.