Opus Krokus :
we won’t be able to fully replace our existing computers with quantum computers
I am just curious... Why?
Someone correct me if I'm wrong, but I think it boils down to the fact that quantum computers rely on entanglement, which so far requires extreme conditions to maintain and only scales up to dozens (or a couple thousand, in D-Wave's case) of qubits.
Compare that to classical computers that have billions of transistors that'll happily operate to near the boiling point of water, in fairly RF and EM-dense environments. So, while you can build very sophisticated logic circuitry out of semiconductors, you're practically limited to using qubits to do things that only qubits are really good at doing (and don't require very many of them).
If entanglement could be scaled up, then simple things, like data movement, could be revolutionized. Imagine being able to send data without any wire or even line-of-sight between two endpoints. This is the bedrock of quantum communications, and people are already doing it. But, what if you could scale it up to replace most of the electrical interconnects computers currently use to move data?