Glass actually had a really good use case, but it's the one thing they explicitly called out in the terms of service as banned:

Facial Recognition

The killer app for Glass would have been the thing that put a little nametag over the head of the person you were looking at, provided you'd met them before. So that you could say "Hey Steve!" to your kid's classmate's dad that you'd met 3 times before and still couldn't remember his name.

Way better than today's tech of saying "Hey!..." then introducing him to your friend Bill and hoping Bill asks his name or he volunteers it. Then hoping you're remember to memorize it this time.

Glass woulda fixed that. But it would have made everything else worse.