I chose slightly important but I think it depends on the dog.
My dogs have never had obedience training.
We have a hawk problem so Gus is always on a leash when outside. If he was allowed to run free I would worry about him seeing an animal, losing his little mind and taking off. Other than that he listens very well.
My first yorkie was the best dog I've ever owned. Once he knew a command word he obeyed without fail. He was allowed to run free - he was a big yorkie and this was before I knew hawks attacked dogs - he never ran away and if he drifted too far, came back immediately when I called.
If I had a dog that wouldn't obey, I would think it very important.
I'm with them 24/7 so that might make a difference. And if we were any closer I don't think I could stand it.