I wonder if they are profitable, or if some sort of government support is involved. I don't think power for all those lights is particularly cheap in Singapore, and the competition in the surrounding countries has cheap labor and lots of free sun and rain.
That's a hard thing to have introspection in as just about every productive source of food probably has some government support.
Just about everywhere has understood "bread and circuses" and "let them eat cake" to the point of monetarily promoting food production.
One of the big distinctions between feudalism and extreme capitalism in my mind is forgetting this.
If you look closely enough, everything is government supported. However farming is explicitly government subsidised everywhere.