No need.
Over Two thirds of all 747s sold were bought for the RANGE, not their size. Well now you don't need to go big to go far. The 747 was not killed by the 380. It was killed by the 767 and the 777.
BTW, if you throw out out all the 747s that were sold for range instead of size, then boeing only sells about 300-400 of them over the last 35 years and the program is a gigantic flop. (just like the 380 would be if Airbus actually had to pay all the developement costs)
Cheers
Wino