tl;dr: LEDs use up to 90% less energy than incandescent bulbs and offer unprecedented control over color, intensity, and timing, but most cities have simply swapped old "dumb" lights for new "dumb" LEDs—often blue-heavy ones that worsen light pollution, disrupt circadian rhythms, and harm wildlife. The DALI protocol enables networked, dimmable, tunable streetlights that could dynamically adjust brightness, protect migrating birds, and even restore views of the Milky Way. France has begun mandating reductions and creating dark ecological corridors, showing the tech's potential is real—but most of the world's thinking about nighttime lighting remains stuck in the past.