Some thoughts about things that use plasma:

Metalworking: Inexpensive plasma cutters make it so there can be one in every garage. Try one, it 's like having a tiny light saber you can cut anything metal with.

Photography: LED's are not quite fast enough to stop motion of a bullet. Air gap illumination still has a place.

Lighting: LED's are neck and neck with fluorescent tubes for efficiency. Cold weather performance, better color, less degradation over time, as well as lower cost in the future may see fluorescents fade away.

Lightning: If global warming leads to more extreme weather, You may be seeing a lot more natural plasma.