Sun is good, but has limitations

It has UV, which stresses out the cells You can't PWM the sun, it's hard to get full naked coverage in front of it. Doesn't perfectly target NIR or NIR-II biological windows.

But for a base/starter, it can't be beat.

Simply put, light is better than no light.

I don’t think people realize how much brighter the sun is than almost all other light sources in their life.

LED headlights in some vehicles are a close second.