I’m struggling with the utility of this logic. The argument seems to be "because malware can intercept /proc output, any tool relying on it is inherently unreliable."

While that’s theoretically true in a security context, it feels like a 'perfect is the enemy of the good' situation. Unless the author is discussing high-stakes incident response on a compromised system, discarding /proc-based tools for debugging and troubleshooting seems like throwing the baby out with the bathwater. If your environment is so compromised that /proc is lying to you, you've likely moved past standard tooling anyway.