Google glass never actually “launched” in any meaningful sense of the word, and was a rough-as-fuck user experience.
Ironically what did it in was the ability to record video. People were so panicked about being filmed that they started reacting violently to glass users (called glassholes). From that point on it sort of became a laughing stock. Not cool. A tainted product.
Apple seems to have mitigated the obvious pitfalls, let’s see how it shakes out.