Macro photography doesn’t need to be shot at ISO 32000; but you can do it with just a little bit of help from a flash.
When you think about macro images, we often imagine those really, really detailed close up photos. As long as there is good lighting, it’s simple to do with focus stacking or even just stopping the lens down with enough light in the scene. Many photographers on their spare time adore the meditative act of fixating on an object and photographing it to get every single detail of the subject. These objects are typically small toys, food, insects, plants, etc. It’s fun and requires the photographer to make a number of very repetitive but careful movements. But of course, every bit of lighting is always useful and we don’t always have good lighting naturally around. But don’t worry: using a flash in this situation is pretty much brainless.