Well, I disagree with the premise.

But perhaps one of the more obvious physical examples are Blue and White LEDs (1992). Small gadgets used to always have red LEDs, maybe green ones, or an unlit 7 segment display, everything else was too expensive or too energy consuming for battery powered devices. And not only that, RGB Diodes also saw the end of pretty much all cathode-ray tubes.

You see kids, back in the olden days before white LEDs, the only way to get blue light was to throw high energy electron ray on a phosphor coating. So anything blue or white before the 90s was made with that technology, from car radios to TV screens.

I'd personally also keep an eye out what the cheap electric motor will do next. From "hoverboards", civilian drones, e-scooters and the modern e-bike, it's only a matter of time before the new use case will emerge.