The 380 as well as the 748 fell victim to the same kind of change in the market. Both were made with the Superhub concept in mind. They were built to connect Frankfurt to NY, Dubai to London, Singapore to Europe and so on. This also worked after a fashion. Looking at Zurich, one of the smaller hubs, EK still filled 2 A380ties daily with folks to feed the Dubai hub, Singapore filled their 380 as well. So did others between the hubs. The idea basically was, to get those huge planes to do the long range work and then distribute the pax off to the smaller airports via feeders.
However, people like direct flights. So the newer long haul smaller planes such as the A350 / B787 turned up, they could do that, transport a smaller number direct to smaller airports, without the need of feeders. Passengers also don't necessarily like megahubs, as they are stressful to change airplanes in, have long immigration queues e.t.c. Add to that the increasing pressure on inner-European flights just for example with environmental taxes e.t.c, the feeder concepts were no longer attractive.
IMHO, this is why the super cathegory failed, for the time being. I somehow think that in a couple of years, once Covid is ancient history and people will want to fly again, they might be sorry to throw them away so quickly.
Also I think the main reason the A380 is totally gone now is that they never made a freighter out of it. Cargo, as opposed to pax traffic, has increased recently and high volume cargo planes would be in demand. Airbus could have replaced the An124's with a proper Cargo 380, but they chose not to do it or rather the concept of the 380 relied on the 2 deck layout so they could not.