Like most parents, once DC transitioned to his own room we got a baby monitor.
And have used it ever since.
DC is now 3.5 (moved out of a cot bed age 3) and I realised (maybe purely out of habit) we still use the baby monitor.
I don't think we even look at it any more - it's just been so routine it never occurred to us to stop.
So maybe it's time to give it up.
When did you stop using the baby monitor?