Originally Posted by
Kerosene Kraut
The 747 had to and could grow over several engine generations to become some success as the 747-200 (mostly used for range) and big success as the 747-400 (perfectly paired with the 767 back then).
The A380 was meant to become a family of aircraft. It's like the A319 member of the A320 family. Closing the program after only one version and generation now is a bit of a change of mind. Where is the stamina Boeing had with the 747?
Actually, size wise, the 747 didn't 'grow' meaningfully from the -100 through the -400 (the stretched upper deck on the -300/400 added some seat area (and the -400 winglets increased the wingspan a bit), but the overall aircraft dimensions didn't change much (except of course for the shorty 747SP). It wasn't until the 747-8 that the 747 was stretched with plugs both fore and aft of the wing. What did increase was the MTOW , which combined with more powerful and efficient engines provided large improvements in range and payload.
Unlike the A380, Boeing considered all the various 747 models to be profitable (although the -8 may not be - the jury is still out) so it made sense to keep reinvesting to make it better and keep it profitable. The A380 has never been profitable - and was only cash flow positive for a few years. Given it was already considered to be too big, spending billions to make it bigger was unlikely to meaningfully improve it's marketability enough to justify the investment.