LED lighting wouldn't exist if not for blue LEDs. And neither would much of modern display technology. The importance of this discovery was not because we could make shiny blue light with it.
LED lighting in practice is typically terrible (though not always or inevitably): the spectrum is too blue and too spiky, without due respect for human needs. It has ruined nighttime lighting, especially outdoors in applications like street lamps, car headlamps, camp lamps, and flashlights. Whatever marketing people are making decisions in the lighting industry have insufficient understanding of human color vision and/or just don't care, consumers or other people making purchasing decisions have poor understanding of the options and their effects, and government regulation has not kept up with the technology.
Agreed on all.
I'd like to add it also pains me that the power to produce about five times more light for the same electricity expenditure has been given without question or qualification to most of humankind, and yet almost no-one seems to ask themselves whether keeping spending the same energy and producing about five times as much light is what they should be doing...
Yes, the thought has occurred to me.
This one seems particularly egregious, since it often results in going from a reasonable quantities of decent quality light to noxious quantities of noxious quality light.