The QR code method incentivizes the latter. No one scanning a random QR code has just dumped their own cartridge.
The search for a Chrono Trigger DS ROM QR code often involves users looking for a way to quickly install the game on a modified Nintendo 3DS using tools like chrono trigger ds rom qr code
Even if you avoid malware, many QR-linked ROMs are garbage. Common issues include: The QR code method incentivizes the latter