Comparing like-for-like, the A380 does just fine if you configure it with equal comfort cabins. And if you can fill it. Now we compare the A380 economics to more modern alternatives, Airbus' A350-1000 and Boeing’s 777-9.
Configured to equal comfort standards the A380 is surprisingly competitive on seat mile costs to the A350-1000 and 777-9.
We then lowered the A380 seat count from Airbus' latest proposals, to find the cross-over point. It's pretty close to Emirates two-class A380s.