EC261 vrey specifically puts the requirement on the operating carrier. This is a specific consumer law in Europe that puts the onus on the operating carrier to fix the issue

In other regions, QR can just cancel flights and get out of it by just cancellimg the ticket and leaving the travel agent to refund or look for availability to rebook

QF went above and beyond what it was required to do in assisting the passenger and does deserve credit for doing so - it was not just doing its job