I have really learnt so much from this thread. I feel like the discussion now needs to heads towards Mining. How Quantum Computers could affect mining and Decentralized aspect of the CryptoCurrencies. One of the thing which is mainly agreed in this thread is a move will be made towards "Quantum resistant Algo", which will prevent Quantum computers to break private keys but what about mining? Given that Quantum computers will be only a few in numbers, Basically these few "companies" would become the centralized figurehead for "Cryptocurrencies". Since there won't be a mining competition how will "cryptocurrencies" survive? Since currently, One of the reasons why people use Cryptos is their Decentralized aspect.

I will give FB's Libra's example. E.g FB gets their hand on one of few early "Quantum computers" they could basically make Libra stand out because it will be the only coin with the most "hashing" power / most secure, but they could easily decide which coin lives and which dies. Basically, if mark then wanted to mine BTCs, even after implementing the "Quantum Resistant" algos, Mark could just mine every block since he will have the most "hashing" power. I'm not familiar with How "Anti Asic" algos for mining work, but could in theory "Anti Quantum" algos could be made for Mining which could prevent this Centralization?