The factor keeping quantum out of taking down the network is room temperature semiconductors. Quantum computers generate a lot of heat and consume a lot of energy. A coordinated quantum attack on every computer running a bitcoin node would be what would change the bitcoin code and have it work. So basically many quantum computers on every internet network in the world where bitcoin is running. It’s not possible because both governments do not trust each other, And that level of quantum computing is not available in all parts of the world. But a quantum computer brute forcing one wallet that is pretty easy. For your wallet to be targeted specifically it would need someone to really attract a lot of attention from someone with access to a quantum computer and who would be willing to use it nefariously, So it would be a pretty specific situation. Quantum computers are for solving problems like how much rocket fuel you need to get to mars, Not cracking bitcoin wallets. Besides this the fact that banks hide trillions of dollars offshore for drug cartels is a more obvious and easy to prove catch of criminal behavior than money hidden in bitcoin.