timmmay: Ambient light isn't some magical light that should always be used. I can improve almost every image with flash, a little or a lot, but I have quite a bit of knowledge and experience. I'm comfortable at ISO6400 but flash lets you highlight what's important in an image.
For context, I'm a wedding photographer. Professional.
Sure, of course. Particularly for wedding type photography, where your subjects are usually close enough to be meaningfully lit up by the flash.