Actually, in times where there is no route on the planet that warrants an A380, it’s better to send them on the routes with little to no passengers so they can carry a useful freight load. Putting them on routes where they could get a passenger load of 50-60% but on a reduced frequency, the freight capacity would be down massively. Whereas a 77W could easily carry 20-30 tons of cargo in addition to half a load, and can carry a good 50-60 tons on freight only services.
In reality, Emirates is probably wishing some of those A380s were 787s right now, but that’s what they have to play with.
In answer to your last question, this Wednesday’s MAN-DXB had 139 pax and Thursday’s had 87. For comparison, Etihad carried 11 passengers on both days.