Every manufacturer looks for new ways to improve their a/c systems, etc, and reduce weight wherever possible while proving a new design. Weight savings on the airframe means more revenue carrying capability (freight and pax) and less fuel spent pushing the plane through the air, especially taking off which uses more fuel per minute than any other sector of flight.
That being said:
- Airbus chose to go from 3 hydraulic systems to 2 in order to simplify the design and maintainability, and reduce weight. Also, the pressure of those systems increased from 3000 psi to 5000 psi (as in fighter jets), and the lines are much thinner, translating into weight savings by lack of an additional hyd fluid reservoir, pumps/filters and associated plumbing and fluid.
- The lack of outboard thrust reversers is also for weight reduction, simplification,
and reducing the possibility of FOD being sucked into the engines on the taxi- and runways, since the a/c is so wide.
Stopping the A380 isn't that big a deal - it's going slower on landing than it appears.
Weight reduction and simplification are always part of the design; achieving them is the hard part.
Hope that I answered most of your inquiry to your satisfaction.
Cheers, y'all.