Even still. Quantum computers wouldn’t become much of a threat until they’re in the thousands or tens of thousands of qubits. ~36k qubits would break a hash in a year of compute. Best quantum computer now is ~500 qubits. It’s uncertain whether or not it’s physically or economically possible to get to the 10s of thousands anyway. Besides, it would be more profitable to just mine with it or we can always upgrade to 512 or a quantum resistant algo, thereby ending the quantum threat permanently. 

 Quantum computing as a field is obvious bullshit https://scottlocklin.wordpress.com/2019/01/15/quantum-computing-as-a-field-is-obvious-bullshit/ 

 Yes, I am highly partial to this.