The worlds largest, and tallest building, should be a vertical farm, in a major city, with natural and LED lighting.
Get to work billionaires... What the heck do we even have you people for?
You know... I remember, back in "the good old days" before I was born, and human beings had rights, we just had millionaires... but still, every few years one of them would build the tallest building the world has ever seen. Giant monuments of pure ego, with office space, that barely paid for itself over the course of a generation.
We're in the internet age. We don't need as much office space as we used to... You know what we do need? Food... In cities, sustainably grown. Prove to society why it's awesome to let you be rich... Otherwise, we're not going to let you stay this rich that much longer.
What's the point of having monumental record breaking wealth, if you're not going to build giant monuments people want to see anymore?
PS As oil prices rise, there is profit to be made here. Restaurant at the top of the world, grocery store at the bottom.