Re: Why not a cargo version
The cargo version exists, but the B747 has better economics. Apparently the belly/main floor cargo economics didn't work on the A380... Remember that on the B747, the upper deck remains for self-loading cargo, there were *no* freight bits up there. On the A380 you would have a whole upper deck that would remain empty (unless you strengthen the floor, which adds weight, which reduces the economics, which...)
FedEx, UPS and DHL all were interested in a freight version of the A380, but then the B777 enhancements happened, the A380 was delayed multiple times, and the companies went for other planes (like the A330 and the older B747s that were being withdrawn).