"We'll upgrade when it matters" only works if the threat stays hypothetical.
Quantum computers are operational today, which means the rebuild everyone postponed is no longer a future problem.
It's a scheduling one.
Bitcoin can't vote itself quantum-safe. Fixing its cryptography needs the whole network to agree, and that never happens fast.
Every transaction in DAC moves through a protected flow from the first block.
Built in at the protocol level, working from day one.