If I'm on a long ride and on a multi use path with very little traffic of pedestrians and such, I like to stretch out by sitting in an upright position. That requires me to let go of the bars. If there's no cross winds, then I can go for quite a while.

It also allows me to drink from the water bottle or even break open a gel pack and take that too.

Cose to home, when I finish my ride and just warming down, and because I know my neighborhood, I can go no hands even on turns, as long as I make the turns wide enough.

Some bikes are very responsive. Some call it twitchy others call it aggressive geometry for quick handling. Those bikes require more skill to go no hands.