The world economy is fragile & the aviation sector is at the mercy of that fragile economy.
More importantly, perhaps Airbus should have been watching Boeing research into the market for larger capacity, longer range aircraft?
Boeing had considered larger-capacity versions of the 747 several times during the 1990s and 2000s (Boeing New Large Airplane). The 747-500X and -600X, proposed at the 1996 Farnborough Airshow, would have stretched the 747 and used a 777-derived wing, but it did not attract enough interest to enter development. In 2000, Boeing offered the 747X and 747X Stretch derivatives as alternatives to the Airbus A3XX. This was a more modest proposal than the previous −500X and −600X. The 747X would increase the 747's wingspan to 229 ft (69.8 m) by adding a segment at the root. The 747X was to carry 430 passengers up to 8,700 nmi (16,100 km). The 747X Stretch would be extended to 263 ft (80.2 m) long, allowing it to carry 500 passengers up to 7,800 nmi (14,400 km). However, the 747X family was unable to attract enough interest to enter production. Some of the ideas developed for the 747X were used on the 747-400ER.
Finally Boeing built the 747-8 largely from the 747-400 base plus existing Boeing technology and has sold 130 at December 2018, whilst the Airbus A380 was a €25 billion new technology project, 234 currently sold and in service and it appears production will cease in the very near future.
Interestingly of the 130 B747-8 delivered so far, 84 (64.6%) were 747-8F freighters. Boeing 747-8 base price $403.6M for 410 pax, three class seating, versus US$445.6M for the A380, typically 555 pax, three class seating.
I wonder whether surplus A380s may eventually turn up in cargo configuration, or whether that is even possible.
The A380 is a great aircraft, hope they survive into the future.