There are so many activities and professions where your hands get dirty and touching a smartphone without washing them would be a bad idea. An auto mechanic could use these glasses to look up information about things they see inside of an engine without having to clean the oil from their hands. A chef could respond to messages about their food delivery without having to drop what they're doing and go sanitize. Anytime I do dirty work outside, I can use this to access smart features without the risk of dirt filling my smartphone case, my smartwatch getting destroyed in a tight situation, or drenching either of them in sweat.
Furthermore, a phone (or a smart watch) is not meant to be used at face level, meaning folks typically look down to use them, and this can lead to extended periods of bad posture resulting in head, neck, and spine problems. My X-ray shows I have bone spurs on the vertebrae of my neck because I look down at screens too much (according to my chiropractor). A smart device that's designed to be used in a way that aligns with good posture habits is absolutely needed.
I hope smart glasses take off and I commented Meta for taking them this far.