I disagree - a reliability incident is temporary, a security incident is permanent
One for a gentle discussion over a beer, but I class security vulnerabilities as fundamentally different because you can't recover from data theft. The exfiltrated data has been copied, and from that point on you've lost control of it. It's a permanent loss. In my neck of the woods, where I'm dealing with medical data, clinical trials data, and biometric data, such a loss can cause someone significant damage up to and including threat to life. Even less obviously deadly data, like that stolen from University of Manchester in summer 2023, can be life-changing - student accommodation data included stated gender and, in some cases, sexuality data for students from countries where non-cis, non-hetero people can be jailed or killed.
Clearly one looks at any system through the lens of risk, but I do think that some of the security risks are qualitatively different in most systems.