As noted, we are taught to shoot until the threat ends. In a situation like this, with both officers and suspect moving, shots are going to miss, or hit “peripheral” areas.
The Taser is not an appropriate weapon in such a circumstance, they simply are not reliable enough. I just watched a video in a very similar circumstance, a man with a knife advancing on a female officer. She shoots him with the Taser, and he dutifully falls down.... And almost immediately gets up and continues his attack, stabbing her (fortunately in the vest). The officers end up shooting him....
In cases like this.... What do you do? The fellow is having perhaps a psychotic break, or he’s in full drug-induced paranoia. He’s armed, and is dangerous to anyone around him.
You’re not likely to call a “mental health worker” to “de-escalate this fellow while he’s armed and charging around at people. You can’t talk them down as they are far from rational... They’re not even hearing you.
These are extremely dangerous and volatile situations that can go south in an instant.