How do I keep on-call incidents dropping over time?

You have built something most teams only wish for. Your incidents trend down because you fix causes, not just symptoms, and the pager gets quieter instead of louder. That is discipline paying off. Take a moment to respect the work that got you here. The risk when things run well is that the discipline quietly relaxes. Reviews get shorter, follow-ups slip, and the old habits creep back before the metrics warn you. Reliability is not a state you reach and keep. It is a practice you either maintain or lose. So protect the habit that made this work. Keep every incident earning its review, and keep the follow-through visible so it stays a shared value, not just your personal standard. And teach it to someone else. A quiet pager that depends on you alone is fragile. One the whole team knows how to keep quiet is real.