Reliable means you show up when you said. It doesn’t mean you’re always available.

Reliability is about keeping the specific promise, not about being endlessly reachable. The two get merged, and then being good at the first is used as grounds for expecting the second. Someone who arrives when they said and does what they said is reliable even if they are unavailable most of the time. Always on is not a stronger version of dependable, it is a different thing with a worse outcome.

Keep the next two commitments you make exactly as made, and let something you did not commit to go unanswered for a day. Reliable and available are separate claims. Only one of them is worth building.