.... additionally digging into the history of the 747 reveals some fundamentals as to why the 380 is the prime victim of a slowdown like the one Covid19 now presents. (This is taken from Wikipedia with slight redactions for coherence)
The original design of the 747 included a full-length double-deck fuselage with eight-across seating and two aisles on the lower deck and seven-across seating and two aisles on the upper deck. However, concern over evacuation routes and limited cargo-carrying capability caused this idea to be scrapped in early 1966 in favor of a wider single deck design.
This shows, that the Boeing engineers realized already in 1966, that two decks of passengers for one deck of freight would hamper the commercial viability of an airliner
At the time, it was widely thought that the 747 would eventually be superseded by supersonic transport aircraft.
This shows, that Boeing did not fall for the hubris of thinking that their design would be the cherry on the pie for eternity and therefore:
Boeing responded by designing the 747 so that it could be adapted easily to carry freight and remain in production even if sales of the passenger version declined. Additionally they wanted to conform to the USAF requirements for the studies of a CX-Heavy Logistics System (CX-HLS) aircraft. Such an aircraft needed to be able to be loaded from the front, thus a door had to be included where the cockpit usually was.
The 380 made this unviable with their cockpit design, therefore making a future rebuilt cargo version not competitive enough, especially considering the need for strengthening the middle floor and thus adding too much weight.
The desire to keep the number of engines to four required new engine designs with greatly increased power and better fuel economy
So even in 1966 Boeing knew of the economical disadvantage of more engines (although they then set the limit at 4). Airbus might have set it at a more modern 2 and would have realized the thin economical range of their 380 if having to stay at 4.