Very true, if speaking in general, and referring to "The Allegory of".
Regarding "Sunlight" VS "Artificial", it's sunlight all the way. However, the environment associated with "Artificial" lends it the nod for our purposes. The controlled environment makes all the difference. That, and although "Sunlight" is superior, it's varied intensity throughout the day (low intensity is the issue morning and evening, high intensity wouldn't be an issue with indoor supplementation/control), it's "inconsistency" through the seasons, and limited ability to manipulate long/short days (relative to the level of control indoors) throughout the year hinders the suns use (6 to 1x (e+c).
Were we able to utilize the full intensity of Summer Solstice sunlight in a complimentary indoor environment, "Magic" would happen.