There is a wast difference between Google glasses and hololens.
The industrial application that I was using it worked as a concept, and I mean worked in reality, not what you are talking about. I used it, and it did saved me time and labour, even in that preliminary stage. I don’t know would it work on a larger scale, but that three devices that the whole factory floor had access to were in use the whole time, and in a conservative industry it’s saying something.