When is audio better than a smart-glasses display?
Audio is useful when you want a spoken explanation or when looking at text would interrupt what you are doing. It can communicate more than a compact display comfortably holds, although listening still consumes attention.
Let the content choose the output
A conversation about an idea can unfold naturally in speech. An exact address may be easier to revisit in text. We would avoid squeezing every response into the same format simply because the hardware offers it. Ordinary earbuds also belong in the comparison: glasses should earn their place by improving the actual workflow.
For a short reminder, audio may be enough. For a list of names you need to consult repeatedly, a display or phone may be more convenient. The useful distinction is whether you need to hear the information once, discuss it, or keep returning to a precise detail.