Look outside. Yes, the street just below. What do you see ? A civilisation of phoned zombies. Market is so huge and margins are still confortable. The personal phone is often seen as one of the the most valuable belongings. Early 2000’s PCs were not.
The problem is the technological gap that manufacturers, vendors and networks have to fulfill to offer something really new: real AI embedded with efficient speech control, complete gesture analysis, automatic image or motion recognition in context, embarked VR engines… Exciting innovations are still possible, but the techs are just not ready.
Meanwhile, wearables won’t become profitable. The millions eventually invested doesn’t mean that the next killer device is a wearable. Personally I do not believe in that. Just for the glasses market: it’s driven by design, fashion and apparence of originality. Tech lifecycle does not allow that. Not yet, not on that scale, even for apple. I think these millions are invested for marketing reasons: the release of something-to-wait worth a classic PR campaign, and you’ve got some R&D assets for the next step. The real one.