Smartphones exploded because they introduced a new, better form of input to the general market. Most use cases do NOT require fine precision of input, so buttons were unnecessary, and the market had already tried both few and many buttons. Smart on-screen keyboards and an UI entirely controllable with touch was a revolution people don't want to come back from until they DO need that precision, which is why gaming accessories like the bone exist, but are a niche.

A projector is none of that. A projector is a gimmick. The projector could cost $5 and it would still fail to capture an audience if it wasn't just a side-feature on a more conventional phone.