[sempron64]

This is an excellent example to illustrate an S-curve. There is a certain amount of energy in a photon. It cannot be emitted with less energy. There is 100% efficiency barrier that cannot be surpassed no matter how smart you are.

[jiggawatts]

Sure, but the technology lifetimes and adoption rates have compressed exponentially despite that.

Efficiency is not the only relevant metric, there's also cost, flexibility, lifetime/durability, CRI, etc...

For example, OLEDs are (literally) flexible, but burn out faster then LEDs and are less efficient.

As another example, the light sources for televisions have undergone nearly annual changes! They started with CFL backlights, then side-illumination with white LEDs, then blue light with quantum dots, OLED panels, backlights as controllable grids of LEDs, mini-LED, micro-LED, RGB micro-LED, etc...

We're up to something like 10K dimming zones with the latest TCL panels and 100K is just around the corner.

[TheCoelacanth]

There's still plenty of room to improve lighting.

If you want to light an indoor room to be as bright as the outdoors on a sunny day, you're going to need a lot of heavy, expensive equipment that produces a lot of waste heat (LEDs produce way less than incandescent, but still a significant amount). It's also not going to be a full continuous spectrum of light the way that sunlight is.

[rbanffy]

I think we can stop building new streetlights at the moment we have full daylight illumination on the visible spectrum 24x7 in urban areas. We’ll probably settle for much less and be happy with that.

If we need more light, we can deploy more power generators.