When did you stop rocking your littles to sleep?

If you did no sleep training or cio of any kind, at what age did you stop rocking them to sleep?

We have a 16mo old that thankfully has always been a wonderful sleeper. My husband rocks him for 20min, transfers him to the crib and he sleeps for about 12hrs. I know he has the ability to put himself to sleep as I’ve seen him wake in the middle of the night and sit up or whatever for anywhere from 20min to an hour+ (yes I watched him for a whole hour one night) and put himself back to sleep, never making a peep other than clapping or talking to himself. However if at bedtime or nap time we just try to put him in the crib he loses it.

I was just wondering at what age you stopped doing this for your littles? I’m thinking when we can communicate verbally better but don’t truly know.