Right. Tiny projectors have been done before. Samsung had a smartphone with a projector back in 2014, but nobody wanted it. Some startup called Moviphone has announced a new one for 2027.[1] The use cases have not been compelling and fighting ambient lighting with a small projector is always tough.

Possible use case: projecting menus, ads, and bills on restaurant tables. With a camera and enough automated layout to work around what's on the table.

It might sell to the people who buy refrigerators with displays on the door. Could be useful as a cooking training aid, like cooking videos but present where you need them.

The light bulb form factor is cute but probably not that useful. Most of the light will be aimed in non-useful directions. Look into ultra short throw projectors.

[1] https://moviphones.com/

It's a good thing that most inventors don't fall for the "something vaguely like this has been tried with inferior technology before, and it sucked" line of reasoning, or our world would look very different :)