Every time my dogs and I go for a hike, I practice recalls with them. At the start of their off-leash time, I leave them in a "stay", and I walk far away to call them. The Labraduo is in a "sit-stay" in the photo below.
But, I do accept that there are situations that are simply too difficult for a dog to be off-leash and obedient. For example, if wildlife like coyotes, deer, bears, bobcats or elk are close enough that I can see them, I think it's prudent to rely on a leash rather than on the dogs' training! I also tend to leash the dogs when their body language tells me that they've caught scent of something extremely exciting. Around here, that "exciting scent" could be a mountain lion eating a dead deer, and I sure don't want my dogs barging in on that!
However, those situations are rare. Normally, I can count on a very enthusiastic response when I call the dogs, like Shyla leaping a small rock to get to me this morning!