Quantum computing is fascinating, but it's really early stages, so we don't know what it or where this technology will shape the space. Will it be real quantum computing or a marketing hyped space ? We all know half the AI space isn't even complicated machine learning algorithms.
But the super quantum computers could make the blockchain cryptocurrency double spend philosophy null and void and irrelevant. Brute force attacks are cost prohibitive with normal computers. But brute force with a quantum computer, Still expensive , but possible. And that's today. Just imagine.
Good start here in testing different strategies to combat this possibilities.